Yevamot 61 - Shabbat May 7, 6 Iyar

Rabbi Shimon bar Yochai ruled that the graves of gentiles do not pass on impurity "through a tent" - tuma't ohel. From where is this derived? If a kohen betrothed a widow and then was appointed kohen gadol, he could go ahead with the marriage, as in the case of Yehoshua ben Gamla and Marta bat Baitus. The same would not hold true for a woman who fell to yibum to a kohen and then he became of kohen gadol, even if he had already done maamar with her. Why is there a difference? If a kohen gadol's brother dies childless, he must do chalitza with the wife and not yibum, as she is a widow. Tih would hold true even if she was only engaged to the brother. Can a kohen marry an aylonit? On what does it depend? What about a yisrael?  Rabbi Eliezer made a statement that a kohen cannot marry a ketana, a minor. Is this statement referring to a regular kohen or to a kohen gadol? And what is the issue. Five different readings of this statement are brought - the first two are rejected. There are a variety of different opinions about what is the definition of a zona, who is prohibited to marry a kohen. There is a mitzva to be fruitful and multiply, meaning, to have children. What is the minimum requirement for this? Beit Shamai and Beit Hillel disagree.