Numbers 32:23-27

But if you do not do so, then take note, you have sinned against the LORD; and be sure your sin will find you out. Build cities for your little ones and folds for your sheep, and do what has proceeded out of your mouth.” And the children of Gad and the children of Reuben spoke to Moses, saying: “Your servants will do as my lord commands. Our little ones, our wives, our flocks, and all our livestock will be there in the cities of Gilead; but your servants will cross over, every man armed for war, before the LORD to battle, just as my lord says.”