"K'Imrasecha" implies that Hashem said so in the Torah. Where is this?
Radak: "U'Va'avor Tihyeh Yir'aso Al Pneichem l'Vilti Secheta'u" (Shemos 20:17; He will save you from sin). Even though choice is given to man, if he is straight, Hashem helps him in the good path. Therefore He showed Ma'amad Har Sinai to Yisrael, to open their hearts to the good path, and block them from sin. "Mi Yiten v'Hayah Levavam Zeh Lahem Leyir'ah Osi" (Devarim 5:26) - who will give from man's side, for if they will give, I will help them to fear Me and guard My Mitzvos.
What salvation does he request?
Radak: This is not salvation of the body from affliction, rather, saving the Nefesh from sin. No enemy is mentioned in this or the previous verses. Since I gave my heart for Your Avodah, also You should give to me help!
