What is the gist of Hashem's words to Yisrael?
Radak: After Hashem judges the nations, He will rebuke Yisrael for their deeds, and eradicate the Resha'im from them and leave the Tzadikim - "Az Asir mi'Kirbecha Alizei Ga'avasecha
What testimony will Hashem bring against Yisrael?
Radak: It is about the Bris - "Ha'idosi Bachem Es ha'Shamayim v'Es ha'Aretz" (Devarim 4:26). Those witnesses still exist; they will testify that you accepted Me to be G-d.
Malbim: I will warn you and inform you of the punishment.
Why does it say "Elokim Elokecha Anochi"?
Radak: This is like I said "Anochi Hashem Elokecha" (Shemos 20:2), and you accepted Me to be G-d, to do all that I will command you.
Malbim: Elokim Anochi corresponds to "va'Adaberah" - I cannot desire Korbanos 1 , for this opposes Elokus. Elokecha Anochi corresponds to "v'A'idah Bach" - I am your Judge, to punish you.
Sifri (Shelach 107): "Re'ach Nicho'ach" - a pleasant spirit in front of Me, that My will was done! Perhaps Malbim means that I cannot desire them without Teshuvah. (PF)
