Numbers 2:10

"The standard of the camp of Reuben [will be] to the south according to their divisions. The leader of the descendants [will be] Elizur son of Shedeur.

Numbers 1:5

And these [are] the names of the men who will {assist you}: from Reuben, Elizur son of Shedeur;

Genesis 49:3-4

Reuben, you [are] my firstborn, my strength, and the firstfruit of my vigor, excelling in rank and excelling in power.

Numbers 7:30

On the fourth day Elizur son of Shedeur, leader of the descendants of Reuben:

Numbers 7:35

and for the sacrifice of the fellowship offering, two cattle, five rams, five he-goats, [and] five male lambs {in their first year}. This [was] the offering of Elizur son of Shedeur.

Numbers 10:18

And the standard of the camp of Reuben according to their divisions; Elizur son of Shedeur [was] over their division.

1 Chronicles 5:1

The sons of Reuben the firstborn of Israel (for he was the firstborn, but when he defiled the couch of his father, his birthright was given to the sons of Joseph, the son of Israel, so that he was not enrolled in the genealogy 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, you [are] my firstborn, my strength, and the firstfruit of my vigor, excelling in rank and excelling in power.
1 Chronicles 5:1
The sons of Reuben the firstborn of Israel (for he was the firstborn, but when he defiled the couch of his father, his birthright was given to the sons of Joseph, the son of Israel, so that he was not enrolled in the genealogy as the firstborn,

Elizur

Numbers 1:5
And these [are] the names of the men who will {assist you}: from Reuben, Elizur son of Shedeur;
Numbers 7:30
On the fourth day Elizur son of Shedeur, leader of the descendants of Reuben:
Numbers 10:18
And the standard of the camp of Reuben according to their divisions; Elizur son of Shedeur [was] over their division.

General references

Numbers 1:20
The descendants of Reuben, the firstborn of Israel, their genealogies according to their clans, according to {their families}, according to [the] number of names, every male individually from {twenty years old} and above, everyone who [is able] to go to war:
Numbers 3:29
The clan of the descendants of Kohath will encamp on the side of the tabernacle to the south.
Numbers 7:30
On the fourth day Elizur son of Shedeur, leader of the descendants of Reuben: