Joshua 23:6-13

Therefore be ye very courageous to keep and to do all that is written in the book of the law of Moses, that ye turn not aside therefrom to the right hand or to the left; that ye come not among these nations, these that remain among you; neither make mention of the name of their gods, nor cause to swear by them, neither serve them, nor bow down yourselves unto them; but cleave unto Jehovah your God, as ye have done unto this day. For Jehovah hath driven out from before you great nations and strong: but as for you, no man hath stood before you unto this day. One man of you shall chase a thousand; for Jehovah your God, he it is that fighteth for you, as he spake unto you. Take good heed therefore unto yourselves, that ye love Jehovah your God. Else if ye do at all go back, and cleave unto the remnant of these nations, even these that remain among you, and make marriages with them, and go in unto them, and they to you; know for a certainty that Jehovah your God will no more drive these nations from out of your sight; but they shall be a snare and a trap unto you, and a scourge in your sides, and thorns in your eyes, until ye perish from off this good land which Jehovah your God hath given you.