Pesachim 37 - 43
Five species of bitter herbs and vegetables are listed in the mishna as qualifying for the fulfillment of the mitzvah of eating maror on the night of Pesach.
Five species of grain are listed in an earlier mishna (35a) as qualifying for the fulfillment of the mitzvah of eating matza on that night. There is one interesting difference between the two mishnayos. In the case of maror we are informed that one may combine parts of the different species in order to make up the minimal amount (k'zayis) necessary for fulfilling the mitzvah. While it is certainly true that one can also combine matza baked from wheat with that of barley or oat to make up the required k'zayis of matza, no mention is made of this in the mishna about matza.
Rabbeinu Nissim offers an explanation based on a ruling of Rava in the latter part of our mesechta (115b): If one swallows matza without chewing and tasting it, he has fulfilled the mitzvah of eating matza on Pesach night; but if one thus swallows maror he has not fulfilled the mitzvah. Rashbam explains that the Torah insists on our tasting the bitterness of the maror in order to recall the bitterness of the suffering of our ancestors in Egypt. The technical act of eating which suffices for matza (although one should preferably chew matza as well) is not adequate for the mitzvah of eating maror, which must be tasted.
Since matza need not be tasted, explains Rabbeinu Nissim, there is no reason to assume that we should not be able to combine the different species of grain. And therefore, the mishna need not mention this latitude. In regard to maror, however, we might have assumed that since tasting the bitterness is a prerequisite, combining different species would be ruled out because the taste of one species interferes with the taste of the other. The mishna, therefore, needs to inform us that combining them is permissible, and that the common sensation engendered by all of them is a bitterness which achieves the desired goal - recalling the bitterness of our ancestral experience.
When Wine Turns To Vinegar
When there was a Beis Hamikdash and wine was brought from Judea to be poured as libations on the altar, the wine in Eretz Yisrael never turned sour unless barley was intentionally added in order to create vinegar. Vinegar was then referred to only as vinegar with no surname.
After the destruction of the Beis Hamikdash, it is the wine of the Edomites (Romans) which does not spoil until barley is added, and vinegar now is referred to as "Edomite vinegar."
This observation of Rabbi Nachman is cited as a vindication of the historical conflict between the Jewish nation of Yaakov and the Edomite nation of his brother Esav. When their mother sensed their prenatal struggle within her womb she was prophetically informed that "one nation would achieve power at the expense of the other." (Bereishis 25:23) This seesaw struggle was characterized by the Prophet Yechezkel (26:2) as the boast of Edomite Tyre that "I shall fill up on the destruction"of Jerusalem.
Maharsha explains the relationship between the libations in the Beis Hamikdash and the quality of Jewish wine on the basis of the blessings which Yitzchak gave to his sons. Yaakov's descendants would enjoy the blessings of power and prosperity as long as they properly served Hashem. If they sinned, their power and prosperity would pass over to their adversaries, the descendants of Esav.
So long as Jews brought wine on the altar of the Beis Hamikdash, their wine was blessed from the Source of blessing, just as the rains of the year were blessed through the pouring of water on the altar during the Succos festival. Once our sins brought about destruction and exile, this blessing passed over to the Edomites and their wine.