Joshua 23:12-13

12For if you ever go back and 1cling to the rest of these nations, these which remain with you, and 2intermarry with them, so that you 3associate with them and they with you, 13know with certainty that the Lord your God will not continue to 4drive these nations out from before you; but they will be a 5snare and a trap to you, and a whip on your sides and thorns in your eyes, until you perish from this good land which the Lord your God has given you.