Numbers 32:20-24

So Moses said to them, “If you will do this, if you will arm yourselves before the Lord for the war,

and all of you armed men cross over the Jordan before the Lord until He has driven His enemies out from Him,

and the land is subdued before the Lord, then afterward you may return and be free of obligation toward the Lord and toward Israel, and this land shall be yours as property before the Lord.

But if you do not do so, behold, you have sinned against the Lord, and be sure that your sin will find you out.

Build yourselves cities for your little ones, and sheepfolds for your sheep, and do what you have promised.”