Psalms 106:34 They did not destroy the nations, concerning whom the LORD commanded them:

Psalms 106:35 But were mingled among the heathen, and learned their works.

Exodus 23:32 Thou shalt make no covenant with them, nor with their gods.

Deuteronomy 7:2 And when the LORD thy God shall deliver them before thee; thou shalt smite them, and utterly destroy them; thou shalt make no covenant with them, nor shew mercy unto them:

1 Samuel 15:9 But Saul and the people spared Agag, and the best of the sheep, and of the oxen, and of the fatlings, and the lambs, and all that was good, and would not utterly destroy them: but every thing that was vile and refuse, that they destroyed utterly.

Jeremiah 48:10 Cursed be he that doeth the work of the LORD deceitfully, and cursed be he that keepeth back his sword from blood.