Numbers 32:17

Then we will be ready to march in battle formation ahead of the other Israelites until we have brought them to their land. Meanwhile our families will live in walled cities. They will be safe from the other people who live here.

Joshua 4:12-13

The children of Reuben, and the children of Gad, and half the tribe of Manasseh, passed over armed before the children of Israel, as Moses spoke to them.

Numbers 32:29-32

Make sure the tribes of Gad and Reuben prepare for battle and cross the Jordan River with you. If they do, then after the land is in your control, give them the region of Gilead as their tribal land.

Deuteronomy 3:18-20

Then I gave them the following instructions: 'Jehovah our God gave you the land east of the Jordan to occupy. Now arm your fighting men and send them across the Jordan ahead of the other tribes of Israel, to help them occupy their land.

Treasury of Scripture Knowledge

Summary

But we ourselves will go ready armed before the children of Israel, until we have brought them unto their place: and our little ones shall dwell in the fenced cities because of the inhabitants of the land.

Bible References

General references

Numbers 32:29
Make sure the tribes of Gad and Reuben prepare for battle and cross the Jordan River with you. If they do, then after the land is in your control, give them the region of Gilead as their tribal land.
Deuteronomy 3:18
Then I gave them the following instructions: 'Jehovah our God gave you the land east of the Jordan to occupy. Now arm your fighting men and send them across the Jordan ahead of the other tribes of Israel, to help them occupy their land.
Joshua 4:12
The children of Reuben, and the children of Gad, and half the tribe of Manasseh, passed over armed before the children of Israel, as Moses spoke to them.