Yevamot 83 - 89
The Missing Levites
Although the Torah awarded maaser rishon (the first tithe on agricultural produce) to the Levites, they lost their right to this important source of income because of a penalty imposed upon them by Ezra:
"I gathered them together," writes Ezra of the Jews whom he led from Babylon to Eretz Yisrael towards the end of their seventy-year exile, "and I found no Levites among them." (Ezra 8:15) Upset by the failure of the Levites to join in his effort to resettle Eretz Yisrael, Ezra penalized them that maaser should no longer be given to them. According to one opinion, maaser was to be given only to the poor. According to another opinion, it could also be given to kohanim during their state of impurity which prevented them from eating terumah and therefore rendered them impoverished.
The problem with this explanation, Tosefot points out, is that the mishna (Kiddushin 69a) clearly states that Levites were among the people who accompanied Ezra. This is also evident from the passage (Ezra 1:5) which lists the Levites among those who were inspired to follow Ezra on his mission to rebuild the Beit Hamikdash in Jerusalem.
Rashi (Kiddushin 69a) supplies the solution to this mystery. When the Babylonian ruler Nebuchadnetzar took the Jews into captivity, he ordered them to play for him the music they had played in the Beit Hamikdash. Their heroic response is recorded in Tehillim(137:2-4): "On the willow trees (along the rivers of Babylon) we hung our harps." They cut off their own thumbs to make themselves incapable of playing music and protested: "How can we play the songs of Hashem on foreign soil!"
Levites subsequently born in Babylon did have the ability to play their musical instruments in the Beit Hamikdash, but only the thumbless ones returned with Ezra. This was viewed by Ezra as a blatant lack of interest in rebuilding the Beit Hamikdash and restoring it to its former glory with the music of Levites, and he therefore penalized them regarding maaser.
- Yevamot 86b
The Missing Husband
In order to marry another man, a woman may rely on the testimony of a single witness that her husband died. But if her husband later turns up, she is forbidden both to him and to the man she married in his absence.
If two witnesses, however, testify that he died, and she marries another on this basis, she does not have to leave her present husband, according to the opinion of Rabbi Shimon, even if the former turns up. When this opinion was supported by the Sage Rav, he was sharply challenged by the Sages in Eretz Yisrael: "The missing husband stands before us and you say she does not have to leave the man she married on the mistaken assumption that he was dead!"
The gemara explains Rav's statement by describing a situation in which the court and the public do not recognize the man who claims to be her missing husband. There are, however, two witnesses who claim to know that he is her husband because they have been together with him from the time he left home until now. It is therefore their word against the word of the two who testify that her husband is dead. In such a standoff, if she is certain that this is not her husband, and she marries one of the witnesses testifying that he saw her husband die, we do not require her to leave her present husband.
In regard to the challenge presented to Rav, an interesting question is raised by Tosefot. Since there are two witnesses who say they saw him die, what significance is there in the court and the general public recognizing the man who comes before us as being her husband? In light of the principle that "two witnesses are like a hundred witnesses," if two witnesses against two is considered a standoff, so, too, is two against a hundred.
Tosefot answers his question with an interesting insight into the power of testimony. Something which is obvious to us cannot be contradicted by even as powerful an evidence as the testimony of two witnesses. We may understand his point by comparing this situation with one in which two witnesses testify that it is now night, even though we see clearly that it is day. The testimony of witnesses is valid only to resolve doubts, but not to challenge obvious realities.
- Yevamot 88a