Numbers 2:10

The standard of the camp of Reuben shall be towards the Negev, by their hosts and the prince of the sons of Reuben, Elizur, the son of Shedeur.

Numbers 1:5

And these are the names of the men that shall stand with you: of the tribe of Reuben, Elizur, the son of Shedeur;

Genesis 49:3-4

Reuben, thou art my firstborn, my might, and the beginning of my strength, principal in dignity, and the principal in power.

Numbers 7:30

On the fourth day Elizur, the son of Shedeur, prince of the sons of Reuben.

Numbers 7:35

and for a sacrifice of peace: two oxen, five rams, five he goats, five lambs of the first year. This was the offering of Elizur, the son of Shedeur.

Numbers 10:18

Then the standard of the camp of Reuben set forward according to their armies, and over his host was Elizur, the son of Shedeur.

1 Chronicles 5:1

Now the sons of Reuben, the firstborn of Israel, (for he was the firstborn, but because he defiled his father's bed, his birthright was given unto the sons of Joseph, the son of Israel; and he was not counted as the firstborn.

Treasury of Scripture Knowledge

Summary

On the south side shall be the standard of the camp of Reuben according to their armies: and the captain of the children of Reuben shall be Elizur the son of Shedeur.

Bible References

Camp of reuben

Genesis 49:3
Reuben, thou art my firstborn, my might, and the beginning of my strength, principal in dignity, and the principal in power.
1 Chronicles 5:1
Now the sons of Reuben, the firstborn of Israel, (for he was the firstborn, but because he defiled his father's bed, his birthright was given unto the sons of Joseph, the son of Israel; and he was not counted as the firstborn.

Elizur

Numbers 1:5
And these are the names of the men that shall stand with you: of the tribe of Reuben, Elizur, the son of Shedeur;
Numbers 7:30
On the fourth day Elizur, the son of Shedeur, prince of the sons of Reuben.
Numbers 10:18
Then the standard of the camp of Reuben set forward according to their armies, and over his host was Elizur, the son of Shedeur.

General references

Numbers 1:20
And the sons of Reuben, the firstborn of Israel, by their generations, after their families, by the houses of their fathers, according to the number of the names, by their polls, every male from twenty years old and upward, all that were able to go forth to war;
Numbers 3:29
The families of the sons of Kohath shall pitch on the side of the tabernacle towards the Negev;
Numbers 7:30
On the fourth day Elizur, the son of Shedeur, prince of the sons of Reuben.