Why is "Lema'ani" repeated?
Sanhedrin 98a: Mashi'ach can come only in a totally unworthy generation - "va'Yar Ki Ein Ish" (59:16), "Lema'ani E'eseh" [or in a totally worthy generation - refer to 60:21:1:1].
Rashi: For Me, and for My Kadosh name.
Radak: For My Kadosh name, and for My praise.
Malbim: One who selects a man due to his importance, this is totally for the sake of the one chosen. One who selects a lower man because he needs him, he does so for himself and his benefit, and also for the one chosen; he is a means to get the benefit via him. However, if one selects a lower man, and he does not need him, just he cannot abandon him, for he is his relative, and he fears that if he abandons him, it will be a disgrace, for his name is called on him, this is totally for himself. Hashem says, I do so totally for Myself. I fear for My honor!
What is Hashem concerned for profaning?
Rashi: His name, if He would cut you off. Malbim - it says "u'Mah Ta'aseh l'Shimcha ha'Gadol" (Yehoshua 7:9).
How would Hashem's honor be given to another?
Rashi: [If I would cut you off,] My enemies would say that their idols are exalted. Radak - they would say that their gods afflicted Yisrael, and Hashem could not save Yisrael from their hand.
