Numbers 32:17-21

but we ourselves will be armed, hurrying ahead of the sons of Israel, until we have brought them to their place, while our little ones live in the fortified cities because of the inhabitants of the land.

We will not return to our homes until every one of the sons of Israel has gained possession of his inheritance.

But we will not have an inheritance with them on the other side of the Jordan and beyond, because our inheritance has come to us on this side of the Jordan toward the east.”

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,