1 Chronicles 15:5 - Albert Barnes' Notes on the Bible

The sons of Kohath - The order of the sons of Levi according to primogeniture is, Gershom, Kohath, Merari Genesis 46:11; Exodus 6:16. But the Kohathites, of whom came the priestly family of the Aaronites, had precedence in all respects. To them especially was committed the attendance upon the ark and the bearing of it. Of the six Levitical families mentioned 1 Chronicles 15:5-10 one only was descended from Gershom, one from Merari, and four (Uriel, Elizaphan, Hebron, and Uzziel) from Kohath.