Sukkah 23B

וכיון דמייתא ⁠— כווצא ולאו אדעתיה.

And once it dies, it contracts to be more than 3 handbreadths from the roofing, and it does not enter his mind to fix it because it is not noticeable. In that case, the principle of lavud would not apply, and the result would be a wall that is less than the minimum requisite height.

ומי אמר אביי רבי מאיר חייש למיתה ורבי יהודה לא חייש? והתנן: בת ישראל שנשאת לכהן והלך בעלה למדינת הים ⁠— אוכלת בתרומה, בחזקת שהוא קיים.

The Talmud asks: And did Abaye actually say that R' Meir is concerned about potential death with regard to the sukka walls and that R' Yehuda is not concerned? Didn’t we learn in a Mishnah: With regard to the daughter of an Israelite who married a priest and her husband went to a country overseas, she may continue to partake of teruma as the wife of a priest, as the presumptive status of her husband is that he is alive? Apparently, in the absence of evidence to the contrary, the presumption is that one who is alive remains alive.

ורמינן עלה: הרי זה גיטיך שעה אחת קודם מיתתי ⁠— אסורה לאכול בתרומה מיד!

And we raised a contradiction from a different Mishnah: If one is leaving his place of residence, and in order to preclude a situation where his wife would have the status of a deserted wife he gives her a conditional bill of divorce and stipulates: This is your bill of divorce that will take effect one hour prior to my death, it is prohibited for her to partake of teruma immediately due to the concern lest he die in the next hour. Apparently, there is concern lest one die at any point.

ואמר אביי, לא קשיא: הא רבי מאיר דלא חייש למיתה, הא רבי יהודה דחייש למיתה.

And Abaye said in resolving the contradiction: This is not difficult. This Mishnah, where the presumption is that one who is alive remains alive, is in accordance with the opinion of R' Meir, who is not concerned about potential death. That Mishnah, where there is concern lest one die at any point, is in accordance with the opinion of R' Yehuda, who is concerned about potential death.