Numbers 32:16-24

16Then the Gadites and Reubenites approached Moses and said, “We want to build sheepfolds here for our livestock and cities for our little ones. 17But we will arm ourselves and be ready1 to go ahead of the Israelites until we have brought them into their place. Meanwhile, our little ones will remain in the fortified cities for protection from the inhabitants of the land. 18We will not return to our homes until every Israelite has taken possession of his inheritance. 19Yet we will not have an inheritance with them across the Jordan and beyond, because our inheritance has come to us on the east side of the Jordan.”

20Moses replied, “If you will do this—if you will arm yourselves before the LORD for battle, 21and if every one of your armed men crosses the Jordan before the LORD, until He has driven His enemies out before Him, 22then when the land is subdued before the LORD, you may return and be free of obligation to the LORD and to Israel. And this land will belong to you as a possession before the LORD. 23But if you do not do this, you will certainly sin against the LORD—and be assured that your sin will find you out. 24Build cities for your little ones and folds for your flocks, but do what you have promised.”