• Rebbe Abahu’s rule of psak

The Gemara on the bottom of Daf 42b taught that Rebbe Abahu was leaning on the shoulder of his servant, Rebbe Nachum, while going on the way, and Rebbe Nachum asked him several questions about the rule of psak. Rebbe Abahu explained that מחלוקת ואחר כך סתם הלכה כסתם – In a case where there is a machlokes followed by an anonymous opinion, the halachah is like the anonymous opinion. סתם ואחר כך מחלוקת אין הלכה כסתם – In a case of an anonymous opinion followed by a machlokes, the halachah is not necessarily like the anonymous opinion. סתמא דמתניתין ומחלוקת בברייתא הלכה כסתם – In a case where there is an anonymous opinion in a Mishnah and a machlokes in a Baraisa, the halachah is like the anonymous opinion. In a case of a machlokes in a Mishnah and an anonymous opinion in a Baraisa, the anonymous opinion in the Baraisa does not carry any weight, for if Rebbe, who redacted the Mishnah, did not teach this ruling as an anonymous opinion, how could Rebbe Chiya, his talmid, know that the ruling is definitive? The Gemara challenges Rebbe Abahu with a stam Mishnah in Keilim and a machlokes in a Baraisa, where the halachah was not in accordance with the stam Mishnah, and concludes that in fact, those with precise knowledge of the text of the Mishnah, cited the opinion in the name of Rebbe Shimon. So, it was not a stam Mishnah.

• The waiting period before entering erusin for a nursing woman and a widow

The Gemara rules regarding the waiting period required for a nursing woman and a widow before they are permitted to enter erusin. A nursing woman, צריכה להמתין עשרים וארבעה חודש חוץ מיום שנולד בו וחוץ מיום שנתארסה בו – needs to wait twenty-four months excluding the day the child was born and excluding the day she enters erusin. And a widow צריכה להמתין שלשה חדשים חוץ מיום שמת בו וחוץ מיום שנתארסה בו – needs to wait three months excluding the day her husband died and excluding the day she enters into erusin.

• Why Rebbe Yose prohibits a woman from entering into erusin during אבילות

The  Mishnah on Daf 41a stated: Rebbe Yose says: כל הנשים יתארסו חוץ מן האלמנה מפני האיבול – All previously married women may enter into erusin at once except for a widow, who is forbidden to enter erusin for thirty days because of the mourning following her husband’s death. Rav Chisda questions Rebbe Yose, based on a kal v’chomer. ומה במקום שאסור לכבס מותר ליארס – If in the mourning period during which it is forbidden to launder clothing, which Rashi says is referring to the week that Tisha B’av falls within, yet it is permissible to enter into erusin, מקום שמותר לכבס אינו דין שמותר ליארס – then in a mourning period, during which it is permissible to launder clothing, which Rashi explains refers to the thirty days of אבילות, is it not logical that it is permissible to enter into erusin? How can Rebbe Yose prohibit erusin during this time? After a long analysis and one explanation, Rav Ashi provides an alternative answer : שאני אבילות חדשה מאבילות ישנה – Recent mourning is different than ancient mourning, ושאני אבילות דרבים מאבילות דיחיד – and communal mourning is different that personal mourning. Since the loss we mourn for on Tisha B’av is not a fresh loss, and is a communal loss, the mourning is not as strict, and therefore, entering into erusin then is permitted.

Siman – Magazine. The magazine on psak called הלכה כסתם, had a special “Entering into Erusin” chart detailing which days are excluded from the count for a nursing mother and widow, as well as a feature article on why an almanah cannot enter erusin during the thirty days of אבילות even though she can wash her clothes.