Numbers 32:26-29

Rotherham(i) 26 Our little ones, our wives, our cattle, and all our beasts, shall remain there, in the cities of Gilead; 27 and, thy servants, will pass over, every one armed for war, before Yahweh, to battle,––as, my lord, is speaking.
28 So Moses gave command concerning them, unto Eleazar the priest, and unto Joshua son of Nun,––and unto the heads of the fathers of the tribes, of the sons of Israel; 29 and Moses said unto them––If the sons of Gad and the son of Reuben will pass with you over the Jordan, every one armed for the war, before Yahweh, and the land be subdued before you, then shall ye give unto them the land of Gilead, for a possession.