You shall make no covenant with them is literally “You [singular] shall not cut an agreement to them.” This is the usual way to speak of establishing a treaty or “agreement” (Good News Translation) between two parties. (A different verb is used in 6.4.) The expression may have come from an ancient ritual of cutting up an animal when a covenant was made. (See Genesis 15.) Or with their gods depends upon the one verb make, meaning make no covenant … with their gods.

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .