Presentation in PDF format Study Guide Yevamot 29 What is the law if two women who are relatives of each other (to whom a man can't marry both) fall to one brother for yibum. Are they exempt or do they need chalitza? There is a debate in the Mishna. The Mishna lists outgrowths of this case that are very similar to those in the Mishna of Yevamot 26. Why are they repeated here?  Beit Shamai and Beit Hillel have a debate about the strength of maamar. Rabbi Elazar tries to figure out how strong maamar is according to Beit Shamai - is it a complete act or is it just strong enough to prevent his wife's sister from becoming connected to him if he husband were his brother and died? A different version of Rabbi Elazar is brought suggesting that perhaps it is not even enough to get rid of the zika of her sister. However, that suggestion is rejected based on the case in our Mishna. Rabba asks if maamar according to Beit Shamai is like betrothal or marriage. What is the relevance of his question? They attempt to answer it but are unsuccessful.