What happened to the Mitzvah of Yibum?
Targum Yonasan: That is a special dispensation that applies only where one's brother has died, whereas this Pasuk is referring specifically to where he is still alive.
Why does the Torah insert "Nidah Hi" in this Pasuk?
Rashi #1: It means that such a Bi'ah is rejected and despicable.
Rashi #2 (citing Yevamos, 54b): To forbid Ha'ara'ah, like by a Nidah. 1
Toras Kohanim: To teach us that the Pasuk is speaking about the wife of one's paternal brother, who, like a Nidah, who is sometimes Mutar and sometines Asur, is sometimes Mutar (where the brother died without leaving children) and sometimes Asur
Why is this needed? All the Arayos are learned from Nidah through a Hekesh (Yevamos, 54b)!
Rashi (17:9) writes that Ariri (being childless) applies to all the Kerisos. If so, why was Eshes Achiv repeated? We already know that there is Kares from 18:29!
Moshav Zekenim (17): Refer to 20:21:2:2 and the note there.
Why was "Nidah Hi" written specifically about Eshes Ach?
