What is the meaning of "Ki Yesischa Achicha"?
Rashi: It means 'When your brother incites you'. 1
Rashi (in Menachos, 39b): The word 'Hasasah' is always used in a negative sense.
What are the connotations of "Achicha ben Imecha"?
Rashi: It actually refers to two people - 'Your paternal brother or your maternal brother.
Da'as Zekenim, Hadar Zekenim: A maternal brother is dearer, for both of them came from the same womb. 1 Also, partial brothers are prone to hate each other, due to inheritance (since each reduces the other's share).
Sanhedrin 21b: This hints that a man may be secluded with his mother, but not with other Arayos.
Harei Besamim 1:122: The one enticed is a witness, and joins to kill the enticer. The Rema (CM 33:2) brings from the Ramban that maternal relatives are disqualified from testifying only mid'Rabanan. If one enticed a close paternal relative, one of the witnesses is invalid (a relative), and this disqualifies the rest of the witnesses, so he cannot be killed. We must say that "Bincha" refers to the son of your daughter.
Targum Yonasan: 'How much more so yout paternal brother!' 2
Why does the Torah omit 'a father' from the list of relatives?
Rashi: A father is actually included in the words "asher ke'Nafshecha".
Refer to 13:7:2:4.
What will be the Din if relatives that are not listed entice one to serve Avodah-Zarah?
The Torah taught the closest relatives 1 , how much more so one should not pay heed to more distant ones!
Just the contrary, one asks him to repeat his enticement in front of others, and (if the enticer fears to do so) schemes to get him to repeat his enticement when he is unaware that witnesses see and hear him, and brings him to Beis Din to kill him! (PF, from Sanhedrin 67a)
What will be the Din in the event that the inciter works openly?
Rashi: The Torah only inserts the word "be'Seiser" because that is the way inciters generally operate, 1 but not to preclude one who operates openly.
Da'as Zekenim citing Bechor Shor: Do not think that "Holech Rachil Megaleh Sod" (Mishlei 11:13) applies here. Just the contrary, it is forbidden to cover up for him! Hadar Zekenim citing Bechor Shor
What is the sinificance of the words "Asher Lo Yada'ata ... "?
Rashi: To pour scorn upon Yisrael, who drop so low, since even Nochrim do not abandon the god that their fathers handed down to them.