The Tribes of Israel: Reuben, Gad and Half Manasseh were Required to Assist in Subduing Canaan

But Moses asked the Gadites and Reubenites, “Shall your brothers go to war while you sit here? …

At that time I commanded you: “The LORD your God has given you this land to possess. All your men of valor are to cross over, armed for battle, ahead of your brothers, the Israelites. …