Numbers 32:26-29

26Our children, our wives, our livestock, and all our animals will remain here in the cities of Gilead. 27But your servants are equipped for war, and every man will cross over to the battle before the LORD, just as our lord says.”

28So Moses gave orders about them to Eleazar the priest, to Joshua son of Nun, and to the family leaders of the tribes of Israel. 29And Moses said to them, “If the Gadites and Reubenites cross the Jordan with you, with every man armed for battle before the LORD, and the land is subdued before you, then you are to give them the land of Gilead as a possession.