To whom does "Ervas Achi Avicha" refer?
Rashi: It refers to the wife of his father's brother.
Ramban, Moshav Zekenim: Refer to 18:7:1:2*.
R. Chaim Paltiel: Some say that Ervas Avicha applies to his father. Why does no one 1 say that Ervas Achi Avicha refers to his uncle? The verse says "El Ishto Lo Sikrav." If this were a new Isur, it should have said 'v'El Ishto'!
Perhaps he had a different text in Sanhedrin (54a). Our text says that even the one who holds that Ervas Avicha is his father's wife, can hold that Ervas Achi Avicha is his uncle, for the end of the verse teaches his uncle's wife! - PF)
Why does the Torah refer to one's uncle's wife as "Dodascha'
Sanhedrin, 28b: To teach us that a woman has the same status as her husband, and that consequently, a man may not testify for or against the wife of a step-son. 1
See Torah Temimah, note 33.
Which aunts are forbidden?
Bechor Shor: "Dodascha Hi" forbids even after the uncle dies, just like the sister of his father and mother are forbidden even after his parents die.
R. Chaim Paltiel: The Torah forbids both paternal and maternal sisters of one's parents 1 (verses 12,13). However, here it forbids only the wife of his father's paternal brother. We learn from a Gezeirah Shavah "Dodo-Dodo" from redemption, which is a Mitzvah only on paternal relatives, who inherit each other. (It seems that Moshav Zekenim holds like this, just the first word 'v'Chen' is a printing mistake - PF.)
R. Chaim Paltiel: Similarly, both paternal and maternal sisters of one's wife, and the wife of one's paternal and maternal brothers, are forbidden.
