Numbers 32:28

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 shall be 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 says.”

Moses said to them, “If the children of Gad and the children of Reuben will pass with you over the Jordan, every man who is armed to battle before the LORD, and the land is subdued before you, then you shall give them the land of Gilead for a possession;

but if they will not pass over with you armed, they shall have possessions among you in the land of Canaan.”

The children of Gad and the children of Reuben answered, saying, “As the LORD has said to your servants, so will we do.