Weighty Waiting Options
We often find that the Torah’s description of even simple actions of our great forefathers impart to us a treasure trove of hanhaga, hashkafa, and even halacha. Sometimes though, it is the exact opposite; a halacha is gleaned from the acts of those far from being paragons of virtue. In our parshiyos hashuva we learn fascinating halachic insights from people whom we would not consider role models by any stretch of the imagination.
Parshas Shelach details at length the grave sin of the Meraglim, the spies whose evil report about Eretz Yisrael still echoes, with repercussions continuing to be felt until today. Of the twelve spies sent, only two remained loyal to Hashem: Yehoshua bin Nun and Calev ben Yefuneh. The other ten chose to slander Eretz Yisrael instead, and consequently suffered immediate and terrible deaths. Due to their vile report, the Jewish people were forced to remain in the desert an additional forty years, and eventually die out, before their children ultimately were allowed to enter Eretz Yisrael.
Hashem called this rogues’ gallery of spies an ‘eidah’, literally a congregation. The Gemara famously derives from this incident that the minimum requirement for a minyan is a quorum of ten men, since there were ten turncoat ‘double-agents’ who were contemptuously called a congregation. If ten men can get together to conspire and hatch malevolent schemes, then ten men can assemble to form a congregation for ‘devarim shebekedusha’. This exegesis is duly codified in halacha, and all because of the dastardly deeds of ten misguided men.
Another prime example of halacha being set by the actions of those less than virtuous, is the tragic chapter of the rabble rousers who lusted after meat, and disparaged Hashem’s gift of the Heavenly bread called manna (munn), chronicled at the end of Parshas Beha’alosecha. The pasuk states that “the meat was still between their teeth” when these sinners met their untimely and dreadful demise. The Gemara extrapolates that since the Torah stressed that point, it means to show us that meat between the teeth is still considered tangible meat and one must wait before having a dairy meal afterwards.
There are actually several different ways to understand the Gemara’s intent, chief among them are Rashi’s and the Rambam’s opinions. The Rambam writes that meat tends to get stuck between the teeth and is still considered meat for quite some time afterward. Rashi, however, doesn’t seem to be perturbed about actual meat residue stuck in the teeth, but simply explains that since meat is fatty by nature, its taste lingers for a long time after eating.
Yet, the Gemara itself does not inform us what the mandated set waiting period is. Rather, it gives us several guideposts that the Rishonim use to set the halacha. The Gemara informs us that Mar Ukva’s father would not eat dairy items on the same day that he had partaken of meat, but Mar Ukva himself (calling himself ‘vinegar the son of wine’) would only wait ‘m’seudasa l’seudasa achrina’, from one meal until a different meal. The various variant minhagim that Klal Yisrael keep related to waiting after eating meat are actually based on how the Rishonim understood this cryptic comment.
This, the most common custom, was first codified by the Rambam. He writes that meat stuck in the teeth remains “meat” for up to 6 hours, and mandates waiting that amount. This is the halacha according to the Tur and Shulchan Aruch, as well as the vast majority of authorities. The Rashal, Chochmas Adam, and Aruch Hashulchan all write very strongly that one should wait six hours. The mandated six hours seemingly comes from the many places in Rabbinic literature where it mentions that the ‘meals of a Torah scholar’ are six hours apart. Therefore, this fits well with Mar Ukva’s statement that he would wait from one meal until the next after eating meat, meaning six hours.
Five Hours and a Bit
The idea of waiting five hours and a bit, or five and a half hours, is actually based on the choice of words of several Rishonim, including the Rambam and Meiri, when they rule to wait six hours. They write that one should keep “k’mosheish sha’os”, approximately six hours. Several contemporary authorities maintain that “six hours” does not have to be an exact six hours; waiting five and a half (or according to some even five hours and one minute) is sufficient, as it is almost six hours. However, it should be noted that not everyone agrees to this, and many maintain that the six hours must be exact.
Waiting four hours is first opined by the Pri Chadash, who comments that the six hours mandated are not referring to regular “sixty minute” hours, but rather halachic hours, known colloquially as “sha’os zmanios”. This complicated halachic calculation is arrived at by dividing the amount of time between sunrise and sunset into twelve equal parts. Each of these new “hours” are halachic hours and are used to calculate the various zmanim throughout the day. The Pri Chadash asserts that at the height of winter when days are extremely short, it is possible that six hours can turn into only four halachic hours! Although several authorities rule this way, and others say one may rely on this exclusively in times of great need, nevertheless, his opinion here is rejected out of hand by the vast majority of desisors, who maintain that the halacha follows six true hours. The Yad Efraim points out that if one follows “sha’os zmanios’ in the winter, then he must also follow it during the summer, possibly needing to wait up to eight hours!
Waiting only hour between meat and dairy, a common custom among Jews from Amsterdam, is codified by the Rema, citing common custom, based on several great Ashkenazic Rishonim including the Maharil and Maharai. The Rema himself, though, concludes that it is nevertheless proper to wait six hours.
Interestingly, and shocking to some, the common German custom of waiting three hours does not seem to have an explicit halachic source. In fact, one who delves into the sefarim of great Rabbanim who served throughout Germany, from Rav Yonason Eibeshutz to Rav Samson Raphael Hirsch, will find that they all recommended keeping the full six hours! Yet, there are several theories explaining how such a widespread custom came about. One, by the Mizmor L’Dovid, is that it is possibly based on the Pri Chadash’s opinion of sha’os zmanios. Another hypothesis, by Rav Binyomin Hamburger - author of Shorshei Minhag Ashkenaz, is that their original custom was to wait only one hour like the basic halacha cited by the Rema, following the majority of Ashkenazic Rishonim. Yet, when the six hours mandated by the Rambam and other Rishonim became more widespread, those in Ashkenaz decided to meet the rest of the world halfway, as a sort of compromise. According to this explanation, it turns out that waiting three hours is intrinsically a chumra on waiting one hour.
Bentch and Go
Another opinion, and one not halachically accepted, is that of Tosafos, who posit that “from one meal to another” means exactly that. As soon as one finishes his meat meal, clears off the table and recites Birkas HaMazon, he may start a new dairy meal. Some add that this includes washing out the mouth and palate cleansing (kinuach and hadacha). This is actually even more stringent than Rabbeinu Tam’s opinion, that all one needs is kinuach and hadacha, and then one may eat dairy - even while part of the same meal! It is important to realize that his opinion here is categorically rejected by all on a practical level.
A Day Away
The most stringent opinion is not to eat meat and milk on the same day (some call this a full 24 hours, but it seems a misnomer according to most authorities’ understanding). First mentioned by Mar Ukva as his father’s personal custom, several great Rabbonim through the ages have been known to keep this. Interestingly, this custom is cited by Rav Chaim Falag’i as the proper one, and in his opinion, only those who are not able to stick to it can rely upon a ‘mere’ six hours.
Just Sleep On It
Another remarkable, but not widely accepted, custom is that of sleeping after eating a meat meal. The proponents of this, including Rav Yosef Shalom Elyashiv zt”l, maintain that sleeping causes the food to digest quicker, thereby lessening the required waiting period. It is told that the Chasam Sofer wanted to start relying on this leniency, but upon awakening, every time he tried drinking his coffee it would spill. He concluded that this hetter must not have been accepted in Heaven. The majority of contemporary authorities as well, do not rely on sleeping as a way of lessening the waiting time. The Steipler Gaon zt”l is quoted as remarking that this leniency is the exclusive domain of Rav Elyashiv zt”l, as most people sleep six hours a night and he only slept three hours nightly.
Although there are many different and widespread opinions about the proper amount of time one is required to wait after eating meat, and “minhag avoseinu Torah hi”, nevertheless, it is interesting to note that the core requirement of waiting is based on the actions of those with less than perfect intentions. As it is stated in Pirkei Avos “Who is wise? One who learns from every one.”
L'zechus Shira Yaffa bas Rochel Miriam v’chol yotzei chalatzeha for a yeshua teikif umiyad.
For any questions, comments or for the full Mareh Mekomos / sources, please email the author: firstname.lastname@example.org.
Rabbi Yehuda Spitz serves as the Sho’el U' Meishiv and Rosh Chabura of the Ohr Lagolah Halacha Kollel at Yeshivas Ohr Somayach in Yerushalayim.
 See Mishna Taanis 26b and following Gemara on 29a, that this, the first of five tragedies, occurred on Tishah B’Av.
 Calev’s father’s real name was actually Chetzron. See Divrei HaYamim (vol. 1, Ch. 2, verse 18) and Gemara Sota 11b.
 Bamidbar (Shelach) Ch. 14, verse 27.
 Gemara Megilla 23b, Brachos 21b, and Sanhedrin 74b. See Rashi al HaTorah ad loc. s.v. l’eidah.
 Rambam (Hilchos Tefilla Ch. 8, Halacha 5), Tur & Shulchan Aruch (Orach Chaim 55, 1 & 69, 1), Aruch Hashulchan (55, 6), and Kitzur Shulchan Aruch (15, 1). Many authorities cite this as the source for this law, including the Bach (Orach Chaim 55, 1), Taz (ad loc. 1), Levushei Srad (ad loc 1), Chida (Birkei Yosef ad loc 3), Shulchan Aruch HaRav (ad loc 2), Mishna Berura (ad loc 2), and Kaf Hachaim (ad loc 6).
 For a full treatment of the Meraglim and their intentions, see relevant commentaries to Parshas Shelach, as well as Rabbi Moshe M. Eisemann’s excellent “Tear Drenched Nights - Tish’ah B’Av: The Tragic Legacy of the Meraglim”.
 Another interesting example of this is a potential halacha we glean from Bilaam. The Gemara (Brachos 7a) explains that Bilaam knew the exact millisecond that Hashem got angry and knew how to properly curse during that time. Tosafos (ad loc. s.v. she’ilmalei and Avodah Zarah 4b s.v. rega) asks what type of curse was it possible for him to utter in such a limited time frame (a fraction of a second!) and gives two answers: 1) the word ‘kaleim’, ‘destroy them’ 2) once Bilaam started his curse in that exact time frame, he ‘locked it in’ and can continue as long as it takes, since it is all considered in that exact time. The Aruch Hashulchan (Orach Chaim 110, 5) takes the second approach a step further and applies this idea to Tefilla B’Zmana. As long as one starts his Tefilla before the Sof Zman, it is considered that he ‘made the zman’ even if the majority of his Tefilla actually took place after the Sof Zman. Although not everyone agrees with this [indeed, many poskim, including the Magen Avraham (Orach Chaim 89, 4 and 124, 4),Pri Megadim (Orach Chaim 89, Eshel Avraham 4 and 110, Eshel Avraham 1), andMishna Berura (58, 5 and 89, end 5), are makpid that one must finish his Tefilla before the Sof Zman], nevertheless a similar logic (based on Bilaam) is presented by the Machatzis HaShekel (Orach Chaim 6, end 6), quoting the Bais Yaakov (Shu”t 127) in the name of the Arizal regarding Tefillas HaTzibbur. If such design worked for one as despicable and reprehensible as Bilaam to enable him to curse us, how much more so should it work for us regarding Tefilla B’Tzibbur which is an eis ratzon!
 An additional example of a halacha gleaned from the wicked actions of Bilaam is that of Tzaar Ba’alei Chaim, causing living creatures unnecessary pain. Although the Gemara (Bava Metzia 32a-b) debated whether this halacha is D’Oraysa or DeRabbanan, according to most authorities, including the Rambam (Hilchos Rotzeach Ch. 13, 13), Rif (Bava Metzia 17b), Rosh (ad loc. 30), Sefer HaChinuch (Mitzva 451, end s.v. kasav), Tur (Choshen Mishpat 272, 11), Rema (ad loc. 9), Bach (ad loc. 5), Gr”a (ad loc. 11), SM”A (ad loc. 15), Kitzur Shulchan Aruch (191,1), and Aruch Hashulchan (Choshen Mishpat 272, 2), as well as the mashmaos of the Gemara Shabbos (128b), Tzaar Ba’alei Chaim is indeed D’Oraysa. According to the Rambam (Moreh Nevuchim vol. 3, end Ch. 17) and Sefer Chassidim (666) this can be gleaned from Bilaam’s actions of hitting his donkey. In fact, they maintain that since Bilaam remarked that if he had a sword in his hand he would have killed his donkey on the spot, that is why he eventually was slain b’davka by sword! Thanks are due to Rabbi Shimon Black of the London Beis Din for pointing out several of these sources.
 Bamidbar (Beha’alosecha) Ch. 11.
 Ad loc. verse 33.
 Gemara Chullin 105a, statements of Rav Chisda.
 For example, the Kreisi U’Pleisi (Yoreh Deah 89, Pleisi 3) and Chochmas Adam (40, 13) posit that the waiting period is actually dependant on digestion.
 Rambam(Hilchos Ma’achalos Asuros Ch.9, 28).
 Rashi, in his glosses to Gemara Chullin 105a s.v. asur.
 Although the Aruch Hashulchan (Yoreh Deah 89, 4) maintains that the waiting period starts from when one finishes theseudah that he partook of meat, nevertheless, most authorities, including many contemporary decisors, follow the Dagul Mervavah (ad loc. 1), and are of the opinion that the waiting period starts immediately after one finishes eating the actual meat product and not the entire seudah. These poskim include the Erech Hashulchan (ad loc. 3), Darchei Teshuva (ad loc. 4), Atzei HaOlah (Hilchos Basar Bechalav, Klal 3, 1), Shu”t Moshe HaIsh (Yoreh Deah 16), and the Kaf Hachaim (ad loc. 9), as well as Rav Yosef Shalom Elyashiv (cited in Piskei Halachos, Yoreh Deah, Basar Bechalav 8, pg. 54), Rav Shmuel HaLevi Wosner (Kovetz m’Bais Levi on Yoreh Deah, Basar Bechalav 2, pg. 33), the Debreciner Rav and Rav Asher Zimmerman (both cited in Rayach HaBosem on Basar Bechalav Ch. 3, Question 28), Rav Chaim Pinchas Scheinberg (cited in Shu”t Divrei Chachamim, Yoreh Deah Ch. 1, Question 6), Rav Chaim Kanievsky (cited in Doleh U’Mashkeh pg. 257), Rav Menashe Klein (Shu”t Mishna Halachos vol. 5, 97, 2), the Rivevos Efraim (vol. 5, 516), and Rav Shalom Krauss (Shu”t Divrei Shalom on Yoreh Deah, 25).
 For an elucidation of what exactly Mar Ukva and his father disagreed upon see Toras HaAsham (76, s.v. v’kasav d’nohagin).
 Tur and Shulchan Aruch (Yoreh Deah 89, 1).
 The Rashal (Yam Shel Shlomo, Chullin Ch. 8, 9; quoted l’maaseh by the Shach - Yoreh Deah 89, 8) writes that anyone who has even a “scent of Torah” would wait six hours. The Chochmas Adam (ibid.) writes that whoever doesn’t wait six hours violates “Al Titosh Toras Imecha” (Mishlei Ch. 1, verse 8). The Aruch Hashulchan (Yoreh Deah 89, 7) writes that whoever doesn’t wait six hours is in the category of “HaPoretz Geder” who deserves to be bitten by a snake (Koheles Ch. 10 verse 8).
 See, for example Gemara Shabbos 10a, Ritva (Chullin 105a s.v basar bein), Rashba (ad loc.), Rosh (ad loc. 5), Baal HaItur (Shaar 1, Hilchos Basar BeChalav 13a-b), Lechem Mishna (on the Rambam ibid.), Biur HaGra (Yoreh Deah 89, 2), and Mor U’Ketzia (Orach Chaim 184 s.v. v’chein).
 Rambam (ibid.), Meiri (Chullin 105a s.v. v’hadar), Agur (223), Kol Bo (106, s.v. v’achar basar), Orchos Chaim (vol. 2, Hilchos Issurei Ma’achalos pg. 335, 73 s.v. v’achar).
 Several authorities make this diyuk, including the Minchas Yaakov (Soles L’Mincha 76, 1), Butchatcher Gaon (Daas Kedoshim - Yoreh Deah 89, 2), and the Aruch Hashulchan (Yoreh Deah 89, 2). Contemporary authorities who rely on not needing a full six hours include the Divrei Chaim zt”l (cited in Shu”t Divrei Yatziv, Likutim V’Hashmatos 69; see also Shu”t Yashiv Yitzchak vol. 5, 14), Rav Chaim Brisker zt”l (cited in sefer Torah L’Daas vol. 2, Beha’alosecha pg. 229, Question 5), the Matteh Efraim (Ardit; pg. 28, 4), Rav Aharon Kotler zt”l (cited in Shu”t Ohr Yitzchak vol. 1, Yoreh Deah 4), Rav Shlomo Zalman Auerbach zt”l (Kovetz Moriah, Teves 5756 pg. 79), Rav Yosef Shalom Elyashiv zt”l (Shu”t Yissa Yosef Orach Chaim vol. 2, 119, 5), and Rav Ovadia Yosef zt”l (Shu”t Yabea Omer vol. 1, Yoreh Deah 4, 13 & vol. 3, Yoreh Deah 3).
 Including Rabbeinu Yerucham (Sefer HaAdam, Nesiv 15, vol. 2, 27, pg. 137), Chamudei Daniel (Taaruvos vol. 2, 15), Shu”t Ginas Veradim (Gan HaMelech 154), Perach Shoshan (1, 1), Mikdash Me’at (on Daas Kedoshim ibid., 2), Yalkut Me’am Loez (Parshas Mishpatim pg. 889 - 890 s.v. shiur), Yad Yehuda (89, Pirush HaKatzer 1), Chofetz Chaim (Nidchei Yisrael Ch. 33), Rav Yisrael Yaakov Fischer zt”l (Shu”t Even Yisrael vol. 9, 126, 5), and Rav Chaim Kanievsky shlit”a (cited in sefer Doleh U’Mashkeh pg. 257). Several other contemporary authorities maintain that one should strive to keep the full six hours l’chatchila,but may be lenient in times of need, including Rav Moshe Feinstein zt”l (cited in Shu”t Divrei Chachamim Yoreh Deah 1, 1; and in private conversation with Rav Moshe’s grandson Rabbi Mordechai Tendler), Rav Yosef Shalom Elyashiv zt”l (cited in Shu”t Avnei Yashpei vol. 5, 101, 3 & 4 and Ashrei HaIsh Orach Chaim vol. 3, pg. 441, 10), Rav Shmuel HaLevi Wosner shlit”a (Kovetz M’Beis Levi on Yoreh Deah pg. 34, 3, & footnote 3) and Rav Menashe Klein zt”l (Shu”t Mishneh Halachos vol. 5, 97, 3).
 Pri Chadash (Yoreh Deah 89, 6). Others who rely on his opinion include the Gilyon Maharsha (ad loc. 3), Ikrei HaDa”t (Ikrei Dinim 10, end 5) and Minchas Yaakov (Soles L’Mincha 76, end 1).
 Including the Yad Efraim (Yoreh Deah 89, 1), Yeshuos Yaakov (ad loc., Pirush Hakatzer 1), Maharsham (Daas Torah ad loc.) and the Zeicher Yehosef (Shu”t end 196), who allow one to rely on the Pri Chadash only if one is sick or in times of great need.
 Including the Pri Megadim (Yoreh Deah 89, Mishbetzos Zahav 1), Pischei Teshuva (ad loc. 3), Knesses HaGedolah (Haghos on Tur, ad loc. 6 - 7), Kreisi U’Pleisi (ad loc. Pleisi 3), Chochmas Adam (40, 12), Chida (Shiyurei Bracha - Yoreh Deah 89, 3 - 4), Zivchei Tzedek (ad loc. 2), Ben Ish Chai (Year 2, Parshas Shelach 9), and Chaguras Shmuel (Yoreh Deah 89, 8).
 Rema (Yoreh Deah 89, 1), Maharai (Haghos Shaarei Dura 76, 2), Maharil (Minhagim, Hilchos Issur V’Hetter 5, s.v. achal), Issur V’Hetter (40, 4). Although the Rashal (ibid.) and Taz (Yoreh Deah 89 2) cast aspersions on this custom, the Gr”a (Biur HaGr”a ad loc. 6) defends it as the Zohar’s minhag as well to wait an hour between all milk and meat meals. Relevant to the proper custom in Amsterdam see seferMinhagei Amsterdam (pg. 20, 24 & pg. 52), Shu”t Yashiv Yitzchak (vol. 13, 25) and Shu”t Shav V’Rafa vol. 3, 114).
 There is no mention of a three hour wait in any traditional halachic source, save for one. And, although in Rabbeinu Yerucham’sKitzur Issur V’Hetter (39) found at the end of his main sefer, it does mention waiting ‘Gimmel Shaos’, it is an apparent misprint, as in the full sefer itself (Sefer HaAdam, Nesiv 15, vol. 2, 27, pg. 137) Rabbeinu Yerucham states unequivocally that one “must wait at least six hours”! Additionally, the source cited for his three hour quote is Rabbeinu Peretz, who also actually mandates waiting six hours (Haghos on SMa”K 213). Moreover, it seems likely that Rabbeinu Yerucham is not the author of the Kitzur Issur V’Hetter attributed to him (see Rabbi Yisrael Ta Shma’s article in Kovetz Sinai,Shevat - Adar 5729). For more on the topic of Rabbeinu Yerucham and three hours, see Rav Moshe Sternbuch’s Orchos HaBayis (Ch. 7, note 45), Rav Chaim Kanievsky’s opinion cited in Kovetz Nitzotzei Aish (pg. 860, 32), and Rav Asher Weiss’s Shu”t Minchas Asher (vol. 1, 42, 2, s.v. u’mkivan). Renowned Rabbonim who served throughout Germany who wrote to keep six hours include Rav Yonason Eibeshutz zt”l (Kehillas AH”U - Kreisi U’Pleisi 89, 3), the Pri Megadim (Kehillos in Berlin and Frankfurt - Yoreh Deah 89, Mishbetzos Zahav 1), Rav Yosef Yuspa Haan zt”l (Noheg K’Tzon Yosef - Minhag Frankfurt, Hilchos Seu dah pg. 120, 4), and Rav Samson Raphael Hirsch zt”l (Chorev vol. 4, Ch. 68, pg. 30).
 Mizmor L’David (Yoreh Deah 89, 6). Rav Hamburger’s explanation is found in a letter written to mv”r Rav Yonason Wiener. See Shu”t Nachlas Pinchas (vol. 1, 36, 7) for a similar assessment. For other sevaros, see Rabbi Yaakov Skoczylas’ Ohel Yaakov (on Basar BeChalav, 89, end footnote 1, quoting Rav Shimon Schwab zt”l) and Shu”t Mishna Halachos (vol. 16, end 9).
 Tosafos (Chullin 105a s.v. l’seudasa), Ravyah (1108, cited by the Rosh and Haghos Ashiri to Chullin Ch. 8, 5), Rema (Yoreh Deah 89, 1).
 Rabbeinu Tam’s opinion is found in Tosafos (Chullin 104b s.v. oif).
 Kaf Hachaim (Falaj’i; Ch. 24, 25 - 26). This was also known to be the Arizal’s custom (Taamei HaMitzvos of Rav Chaim Vital, Shaar HaMitzvos, Parshas Mishpatim). See also Shulchan HaTahor (173, 2), Ben Ish Chai (Year 2, Parshas Shelach 15), Shu”t Torah L’Shma (212) and Shu”t Shraga HaMeir (vol. 7, end 105). Some say (see Piskei Teshuvos end 494) that based on his writings on Parshas Mishpatim (s.v. lo sevashel), the Noam Elimelech must have also kept this stringency. However, it is known that there were several Gedolim who held this to mean to wait an actual 24 hours from eating meat before allowing milk products, including the Shla”h (cited by his chaver Rav Yosef Yuspa Haan in his Yosef Ometz,137; interestingly, he writes that he personally could not keep it and instead waited a mere 12 hours!) and the Reishis Chochma (in his sefer Totzaos Chaim, Shaar 2, Hanhaga 45, pg. 32). Thanks are due to Rabbi Eliezer Brodt, author of Bein Kesseh L’Assor and Lekutei Eliezer for pointing out these sources.
 See Daas Kedoshim(Yoreh Deah89, 2), VaYaas Avraham (of Tchechnov; pg. 333, 51 & Ateres Zekainim ad loc. 155), Piskei Teshuva (vol. 3, 285), Piskei Halachos of HaGri”sh Elyashiv shlit”a (Yoreh Deah,Basar Bechalav pg. 53, 6; see also Shu”t Yissa Yosef - Orach Chaim vol. 2, 119, 6 and Ashrei HaIsh - Orach Chaim vol. 3 pg. 442, 15, who claim that Rav Elyashiv zt”l only meant to be lenient after chicken and not actual meat).
 The story about the Chasam Sofer is cited in Zichron L’Moshe (pg. 79), Shu”t Divrei Yisrael (vol. 2, pg. 28, footnote) and in Shu”t Siach Yitzchak (399).
 Including Shu”t Siach Yitzchak (ibid.), Shu”t Teshuvos V’Hanhagos (vol. 1, 431), Kovetz M’Beis Levi (on Yoreh Deah pg. 34, 5; citing the opinion of Rav Shmuel HaLevi Wosner), Shu”t Beis Avi (vol. 3, Yoreh Deah beg. 108), Shu”t Mishna Halachos (vol. 7, 70), Shu”t Shulchan HaLevi (vol. 1, 22, 10, 1), sefer Doleh U’Mashkeh (pg. 257 - 258 and footnote 15; citing the opinion of Rav Chaim Kanievsky, as well as his father, the Steipler Gaon). This leniency is also conspicuously absent from the vast majority of earlier authorities.
 Tosafos (Menachos 20b s.v. v’nifsal).
 Avos (Ch. 4, Mishna 1).
Disclaimer: This is not a comprehensive guide, rather a brief summary to raise awareness of the issues. In any real case one should ask a competent Halachic authority.
L'iluy Nishmas the Rosh HaYeshiva - Rav Chonoh Menachem Mendel ben R' Yechezkel Shraga, Rav Yaakov Yeshaya ben R' Boruch Yehuda, and l'zchus for Shira Yaffa bas Rochel Miriam and her children for a yeshua teikef u'miyad!