Genesis 29:32

29:32 So Leah became pregnant and gave birth to a son. She named him Reuben, for she said, “The Lord has looked with pity on my oppressed condition. Surely my husband will love me now.”

Genesis 46:8

46:8 These are the names of the sons of Israel who went to Egypt – Jacob and his sons:

Reuben, the firstborn of Jacob.

Genesis 48:18

48:18 Joseph said to his father, “Not so, my father, for this is the firstborn. Put your right hand on his head.”

Numbers 1:20

1:20 And they were as follows:

The descendants of Reuben, the firstborn son of Israel: According to the records of their clans and families, all the males twenty years old or older who could serve in the army were listed by name individually.

Numbers 26:5

Reuben

26:5 Reuben was the firstborn of Israel. The Reubenites: from Hanoch, the family of the Hanochites; from Pallu, the family of the Palluites;

Numbers 26:1

A Second Census Required

26:1 After the plague the Lord said to Moses and to Eleazar son of Aaron the priest,

Numbers 2:1

The Arrangement of the Tribes

2:1 The Lord spoke to Moses and to Aaron:

Numbers 5:1

Separation of the Unclean

5:1 Then the Lord spoke to Moses:

Numbers 5:3

5:3 You must expel both men and women; you must put them outside the camp, so that they will not defile their camps, among which I live.”