- ערוה פוטרת צרותה מן החליצה ומן היבום
The opening Mishnah of the Masechta states: חמש עשרי נשים פוטרות צרותיהן וצרות צרותיהן מן החליצה ומן היבום – Fifteen women, (which the Mishnah will identify as arayos), exempt their co-wives and their co-wives of their co-wives from the chiyuv of chalitzah or yibum. The Mishnah later explains that if a brother dies leaving a wife who is an ervah to the living brother, then not only is the ervah exempt from yibum or chalitzah, but she exempts her co-wives (צרות) from yibum and chalitzah as well. If a second brother was able to do yibum with one of the צרות, since none of the wives were prohibited to him, and he died, this צרה exempts her current צרות from yibum and chalitzah from the first living brother. The same rule applies to the צרות of the צרה ad infinitum.
- חמש עשרה נשים
The Mishnah lists the fifteen arayos of the yavam who exempt their צרות from yibum and chalitzah:
·בתו ובת בתו ובת בנו – His daughter from out of wedlock, or his granddaughters from either his daughter or son from out of wedlock
·בת אשתו ובת בנה ובת בתה – His wife’s daughter, and his granddaughters from either his son or daughter
·חמותו אם חמותו אם חמיו – His mother-in-law, his mother-in-law’s mother, or his father-in-law’s mother
·אחותו מאמו ואחות אמו ואחות אשתו – His sister from his mother, his mother’s sister, and his wife’s sister
·אשת אחיו מאמו ואשת אחיו שלא היה בעולמו – His maternal brother’s wife, and the wife of his brother who died before he was born
·כלתו – His daughter in law
- Four ways the צרה could be subject to yibum
The Mishna continues: וכולן אם מתו או מיאנו או נתגרשו או נמצאו אילונית צריתיהן מותרות – And regarding all of these fifteen women, if they died before he did, or was a minor and did mi’un terminating her marriage to the brother, or they were divorced from him at the time of his death, or were found to be an aylonis, so that the marriage was terminated before the husband died, their tzaros are permitted to do yibum or chalitzah.