Numbers 33:55

But if you do not destroy the inhabitants of the land from before you, it will come to pass, that those of them whom you shall leave, will be thorns in your eyes, and darts in your sides, and your mortal enemies in the land wherein you dwell.

But if ye will not destroy the dwellers in the land from before you, then it shall come to pass that whomsoever of them ye shall leave shall be thorns in your eyes, and darts in your sides, and they shall be enemies to you on the land on which ye shall dwell;