And the men of Reuben, the men of Gad, and half the tribe of Manasseh crossed over armed before the children of Israel, as Moses had spoken to them.
Joshua 4:12
Surrounding context
4:11 Then it came to pass, when all the people had completely crossed over, that the ark of the LORD and the priests crossed over in the presence of the people.
4:12 And the men of Reuben, the men of Gad, and half the tribe of Manasseh crossed over armed before the children of Israel, as Moses had spoken to them.
4:13 About forty thousand prepared for war crossed over before the LORD for battle, to the plains of Jericho.