Numbers 3:19

And the sons of Kohath by their families; Amram, and Izehar, Hebron, and Uzziel.

The four names are the sons of Kohath by their families — Amram, Izehar, Hebron, and Uzziel — dividing the Kohathites, one division of the Levites, into these four family lines. The list is also given as Amram, Izhar, Hebron, and Uzziel as sons of Kohath. The verse belongs to the census account that organizes the tribe of Levi and the tribes of Israel in detail by families and divisions. The census chapters give detailed accounts of Israel's tribes and Levite families, with the Kohathites as one of the Levite divisions.

In that organization the Kohathites were assigned to serve the sanctuary and its vessels. This was a Levite duty distinct from the duties of the priests. The law concerning the Kohathites required their family to carry the ark and sacred vessels on their shoulders, after the vessels had been covered, and they were not to touch them. No oxen were given to this family because they were to bear these holy things themselves.

The verse is part of the order written in the book of Moses for setting the priests in their divisions and the Levites in their courses for the service of God at Jerusalem. That order was followed at the dedication of the rebuilt temple. In its context, Numbers 3 shows that the Aaronic priesthood was established by law for its appointed age, until the type met its antitype.