Numbers 32:29-32

He said to them, “If the Gadites and Reubenites, every man armed for battle, cross over the Jordan with you before the LORD, then when the land is subdued before you, you must give them the land of Gilead as their possession. But if they do not cross over with you armed, they must accept their possession with you in Canaan.” The Gadites and Reubenites answered, “Your servants will do what the LORD has said. We will cross over before the LORD into Canaan armed, but the property we inherit will be on this side of the Jordan.”