Seeing as the incident of Ba'al Pe'or was perpetrated by Mo'av, why does the Torah blame Midyan?
Ramban: Because the plot was devised by the elders of Midyan 1
Ramban: Whom Balak consulted - See Balak, 22:4 - in conjunction with Bil'am..
Seeing as the perpetrarors were Mo'av, why did Hashem not include Mo'av in the command ?
Rashi #1 (citing Bava Kama, 38b): Because Rus was destined to descend from Mo'av 1 .
Rashi #2 (on 31:2): Because, whereas Midyan had no reason to cause Yisrael to sin, Mo'av did so out of fear ? because although Yisrael were forbidden to attack them, they were permitted to plunder them.
Ramban #1: Because Hashem had already forbidden them to fight against Mo'av. 2
Ramban #2: Because Hashem gave the lands of Amon and Mo'av to the sons of Lot. 3
Some say that the B'nos Mo'av did not seduce Yisrael, only the B'nos Midyan. Refer to 25:1:151:1,2 & 5), and the war was to avenge the seduction. (PF)
Gur Aryeh (31:2): The Gemara said 'due to Rus and Na'amah ha'Amonis' (the mother of Rechavam - Shlomo's son). What is the relevance of Amon here? Rather, due to Rus and Na'amah, the Torah forbids war against Mo'av and Amon. The Gemara taught them together to teach that there is one reason ? for the sake of Malchus Beis David. Ben Yehoyada ? Hashem could have commanded to save the men from whom they will descend, and kill everyone else! Had they done so, the fathers of Rus and Na'amah would be commoners. Hashem wanted them to be Benos Melachim. Also see Ramban DH 'va'Ani Tamah' & Sifsei Chachamim.
Ramban: See Devarim, 2:9. See also Ramban (DH 've'Hinei').
Ramban: Because their father Lot served Avraham and accompanied him into exile - into those very lands. Whereas for their sin in distancing Yisrael, they were punished in that they were distanced from Yisrael, Midah ke'Neged Midah ? as the Torah writes in Devarim 23:4 "Lo Yavo Amoni u'Mo'avi bi'Kehal Hashem".
What is the meaning of "be'Nichleihem"?
Rashi (in the original manuscript) and Targum Yonasan: It means 'with their cunning tricks'. 1
Ramban: It means 'with their conspiracies'. 2
Rashi: As in Mal'achi, 1:14. Setting up the shops and seducing the men was in order to trick them into worshipping Ba'al Pe'or - Na'ar Yonasan.
Ramban: Since it was the elders of Midyan who concocted the plan to lead them astray from Hashem, and because they sent their sister the princess to commit adultery with them - See Ramban.
Why did Hashem insert the words "al-D'var Pe'or"?
Rashi: Because the main objective of sending the women to ensnare the men was in order to get them to worship Pe'or. 1
Refer to Bamidbar, 25:2:2:1.
