Rashi on Deuteronomy 2:31/רש"י על דברים ב׳:ל״א

1החלתי 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).