Numbers 1:5

1:5 Now these are the names of the men who are to help you:

from Reuben, Elizur son of Shedeur;

Numbers 2:10

The Tribes on the South

2:10 “On the south will be the divisions of the camp of Reuben under their standard. The leader of the people of Reuben is Elizur son of Shedeur.