NUM 2:10

10 The tribes of Reuben, Simeon, and Gad must set up their tents on the south side of the Sacred Tent, close to their tribal flags. These are the names of the leaders of those tribes and the number of men whom they will lead: Elizur, the son of Shedeur, will be the leader of the 46,500 men of the tribe of Reuben.