Numbers 22:21

And Balaam rose up in the morning, and saddled his ass, and went with the princes of Moab.

Cross-reference

Numbers 22:35 Historical context

Numbers 22:35 repeats the command to go but with the angel's warning — showing Balaam's persistent disobedience and God's restraint.

Proverbs 1:15 warns against joining evildoers — Balaam does exactly that here, going with Moab's princes despite God's later anger.