Charles Ellicott Commentary Exodus 23:32

"Thou shalt make no covenant with them, nor with their gods." — Exodus 23:32 (ASV)

You shall make no covenant with them — that is, no treaty of peace; no arrangement by which one part of the land shall be yours and another theirs. .

Nor with their gods. —It was customary at the time for treaties between nations to contain an acknowledgment by each of the other’s gods. (See the treaty between Rameses II and the Hittites in Records of the Past, vol. iv, pp. 27-32.) Thus, a treaty with a nation was a sort of treaty with its gods.