Judges 11:21

21 and Jehovah, God of Israel, giveth Sihon and all his people into the hand of Israel, and they smite them, and Israel possesseth all the land of the Amorite, the inhabitant of that land,

Judges 11:21 Meaning and Commentary

Judges 11:21

And the Lord God of Israel delivered Sihon and all his people
into the hand of Israel
So that as Sihon, his people, and his country, fell into the hands of Israel through the victory the Lord gave them over him, they had a divine right to the land now in dispute:

and they smote them:
destroyed him and all his people, as they were ordered to destroy the seven nations of Canaan, of which the Amorites were one, ( Deuteronomy 7:1 ) ,

so Israel possessed all the land of the Amorites, the inhabitants of
that country;
by means of the above victory they came into the lawful and rightful possession of all the land that belonged to the Amorites, who were at that time, and none else, the inhabitants of it; and therefore the Ammonites could have no claim to it, nor was any made till now.

Judges 11:21 In-Context

19 `And Israel sendeth messengers unto Sihon, king of the Amorite, king of Heshbon, and Israel saith to him, Let us pass over, we pray thee, through thy land, unto my place,
20 and Sihon hath not trusted Israel to pass over through his border, and Sihon gathereth all his people, and they encamp in Jahaz, and fight with Israel;
21 and Jehovah, God of Israel, giveth Sihon and all his people into the hand of Israel, and they smite them, and Israel possesseth all the land of the Amorite, the inhabitant of that land,
22 and they possess all the border of the Amorite from Arnon, and unto the Jabbok, and from the wilderness, and unto the Jordan.
23 `And now, Jehovah, God of Israel, hath dispossessed the Amorite from the presence of His people Israel, and thou wouldst possess it!
Young's Literal Translation is in the public domain.