Chronicles I 26:10

10 And to Osa of the sons of Merari sons, keeping the dominion; though he was not the first-born, yet his father made him chief of the second division.

Chronicles I 26:10 Meaning and Commentary

1 Chronicles 26:10

Also Hosah, of the children of Merari, had sons
Who was a fellow porter of Obededom's at the ark, ( 1 Chronicles 16:38 ) .

Simri the chief (for though he was not the firstborn, yet his father
made him the chief);
the firstborn being unfit for service, either through want of an intellectual capacity, or of strength of body, or through some defect or another; according to the Syriac version, he was dead; so some understand the words, he, the father, had no firstborn remaining or living.

Chronicles I 26:10 In-Context

8 All of the sons of Abdedom, they and their sons and their brethren, doing mightily in service: in all sixty-two to Abdedom.

9 And Mosellemia eighteen sons and brethren, mighty men.

10 And to Osa of the sons of Merari sons, keeping the dominion; though he was not the first-born, yet his father made him chief of the second division.

11 Chelcias the second, Tablai the third, Zacharias the fourth: all these the sons and brethren of Osa, thirteen.

12 To these the divisions of the gates, to the chiefs of the mighty men the daily courses, even their brethren, to minister in the house of the Lord.