Deuteronomy 3:18-20

18At that time I commanded you, ‘The Lord your God has given this land to you, for you to live in it. But all your soldiers must take their weapons and they must cross the Jordan River. You must go in front of the other Israelite tribes across the river.

19But your wives, your children and your animals may stay here in the towns that I have given to you. I know that you have many animals.

20Your men must fight to help the other Israelites until the Lord gives them a safe place to live. He has already given you a safe place to live. Now you must help the other Israelites to take the land which the Lord your God is giving to them. That land is on the other side of the Jordan River. When they take the land for themselves, you may return here to the land that I have given to you.’