Behold, I have begun to give Sihon. — Notice that in all the conquests of Israel Jehovah gave the order to begin the attack. (See Deuteronomy 7:2, and Note on Joshua 13:1.)
Related Commentaries of Deuteronomy 2:31
Deuteronomy 2:31
31 And the LORD said unto me, Behold, I have begun to give Sihon and his land before thee: begin to possess, that thou mayest inherit his land.