Numbers 32:23-27

But if you will not do so, behold, 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 you have promised.” And the people of Gad and the people of Reuben said to Moses, “Your servants will do as my lord commands. Our little ones, our wives, our livestock, and all our cattle shall remain there in the cities of Gilead, but your servants will pass over, every man who is armed for war, before the LORD to battle, as my lord orders.”