Numbers 32:16-23

Then the Reubenites and Gadites came up to Moses and said, “We will build pens for our animals and cities for our children here. Then our children will be in strong, walled cities, safe from the people who live in this land. Then we will prepare for war. We will help the other Israelites get their land, and we will not return home until every Israelite has received his land. We won’t take any of the land west of the Jordan River; our part of the land is east of the Jordan.” So Moses told them, “You must do these things. You must go before the LORD into battle and cross the Jordan River armed, until the LORD forces out the enemy. After the LORD helps us take the land, you may return home. You will have done your duty to the LORD and Israel, and you may have this land as your own. “But if you don’t do these things, you will be sinning against the LORD; know for sure that you will be punished for your sin.