Numbers 1:20
The generations of the sons of Reuben, the oldest son of Israel, were numbered by their families and their fathers' houses, every male of twenty years old and over, who was able to go to war;
Numbers 26:5-7
Reuben, the first son of Israel: the sons of Reuben by their families: of Hanoch, the family of the Hanochites: of Pallu, the family of the Palluites:
Numbers 2:10-11
On the south side is the flag of the children of Reuben, in the order of their armies, with Elizur, the son of Shedeur, as their chief.
Genesis 29:32
And Leah was with child, and gave birth to a son to whom she gave the name Reuben: for she said, The Lord has seen my sorrow; now my husband will have love for me.
Genesis 46:9
And the sons of Reuben: Hanoch and Pallu and Hezron and Carmi;
Genesis 49:3-4
Reuben, you are my oldest son, the first-fruit of my strength, first in pride and first in power:
1 Chronicles 5:1
And the sons of Reuben, the oldest son of Israel, (for he was the oldest son, but, because he made his father's bride-bed unclean, his birthright was given to the sons of Joseph, the son of Israel; but he is not to be given the place of the oldest.