John Gill Commentary 2 Chronicles 20:7

"Didst not thou, O our God, drive out the inhabitants of this land before thy people Israel, and give it to the seed of Abraham thy friend for ever?" — 2 Chronicles 20:7 (ASV)

Are you not our God
In a peculiar sense, not merely as the Creator and Governor of men, but in a covenant relation their covenant God and Father:

who did drive out the inhabitants of the land before your people
Israel ;
the seven nations of Canaan, to make way and room for Israel:

and gave it to the seed of Abraham your friend for ever ?
made a deed of gift of it to them, and settled it on them till the coming of the Messiah, and that as an instance of love and friendship to Abraham; and will you therefore suffer it to be taken from his seed?