18 "At that time I gave this command to the tribes that would live east of the Jordan: 'Although the Lord your God has given you this land as your property, all your fighting men must cross the Jordan ahead of your Israelite relatives, armed and ready to assist them.
Matthew Henry's Commentary on Deuteronomy 3:18
Commentary on Deuteronomy 3:12-20
(Read Deuteronomy 3:12-20)
This country was settled on the Reubenites, Gadites, and half the tribe of Manasseh: see Numbers 32. Moses repeats the condition of the grant to which they agreed. When at rest, we should desire to see our brethren at rest too, and should be ready to do what we can towards it; for we are not born for ourselves, but are members one of another.