Commentary for Deuteronomy 2:31

החלתי תת לפניך I HAVE BEGUN TO GIVE [SIHON] BEFORE THEE — He cast down the tutelary angel of the Amorites, who was in the upper spheres, beneath Moses’ feet and made him tread upon his neck (cf. Rashi on Numbers 24:2).

ראה החילותי תת לפניך, "Behold, I have begun to deliver up to you, etc." G'd used the word: "I have begun" in the past tense, and the word refers to the time G'd had hardened the spirit of Sichon to deny Israel the right of passage through his country in order to have a pretext to deliver him into Israel's hands. The word החילותי refers to the giving of the land, not to the previous paragraph. Moses misunderstood thinking that the word referred to the whole previous paragraph. This was what caused him to think that G'd had revoked His decree against him and this is what prompted his entreaty at the beginning of the next פרשה as explained there by Sifri.

V. 31. ראה: sein Widerstand ist bereits der Anfang seines Falles. החל רש לרשת את ארצו: fange deine Landesbesitznahme damit an, sein Land in Besitz zu nehmen. Mit Sichons Land beginne deine Besitznahme.