Numbers 22:6

22:6 So now, please come and curse this nation for me, for they are too powerful for me. Perhaps I will prevail so that we may conquer them and drive them out of the land. For I know that whoever you bless is blessed, and whoever you curse is cursed.”

Numbers 33:55

33:55 But if you do not drive out the inhabitants of the land before you, then those whom you allow to remain will be irritants in your eyes and thorns in your side, and will cause you trouble in the land where you will be living.