If one told his wife 'you are to me like my mother' - Bi'ah with you is like Bi'ah with my mother. If he said 'like the flesh of my mother', it has no effect.

Question: If one said 'this loaf is Alai like Bi'ah with my mother, what is the law?

Answer: We learn from the following. One who says to his wife 'Konam, I will not have Bi'ah with you' - Rav said, he is forbidden. Shmuel said, he is permitted.

Question: How does Shmuel fulfill [our Mishnah, which says that] "Lo Yachel Devaro" applies?

Answer: It is as if "Lo Yachel Devaro" [applies].

Rav taught like he taught elsewhere;

Tana d'Veis Rav argues. [He taught,] what is the source for Nedarim, that they are permitted to you from Shamayim, and [some] people conduct Isur (they think that they take effect), that one [who knows that they are permitted] may not vow and annul [it]? It says "Lo Yachel Devaro" - he may not make his words profane. (We explained this like LEV YERUSHALAYIM citing GILYON EFRAYIM.)

[If one said] 'Shevu'ah, I will not sleep for three days' (this is impossible, so it does not take effect), he is lashed [for a vain Shevu'ah] and he may sleep immediately. 'Shevu'ah, I will not eat for three days' (this is possible, but many people will enter mortal danger), we wait until he eats, and we lash him (for a false Shevu'ah).