What is "k'Apecha uch'Kin'asecha"?
Rashi: Like the Af (anger; Radak - and Kin'ah) that you did to Yisrael, I will do to you.
Malbim: You did many evils to Yisrael in Galus, as if it was amidst Kin'as Elokim (zeal to avenge Yisrael's sins against Him) - really it was mi'Sin'asecha (amidst your hatred).
The Yud in "mi'Sin'asecha" indicates plural (hatreds). If so, it should say mi'Sin'osecha!
Radak: We find words in which the plural form is used only in the pronoun at the end, e.g. "Asaperah Kol Tehilasecha" (Tehilim 15:9).
Why does it say "v'Nodati Vam [Ka'asher Eshpetecha]"?
Rashi: When I will judge you, they will recognize My Gevurah.
Radak: I will judge you due to them. Then it will be known that I chose them, and they are a nation to Me [Malbim - and I am their G-d, and the true Emunah will be known].
Radak citing Targum Yonasan: I will appear, to do good to them, when I will exact payment from you.
