Charles Ellicott Commentary 2 Chronicles 17:14

"And this was the numbering of them according to their fathers` houses: Of Judah, the captains of thousands: Adnah the captain, and with him mighty men of valor three hundred thousand;" — 2 Chronicles 17:14 (ASV)

And these ... their fathers. — And this is their muster (or census), according to their father-houses (clans), (1 Chronicles 24:3). The warriors were marshalled in the army according to clans, so that men of the same stock fought side by side with their kindred. Perhaps in the original document this heading was followed by a much more detailed scheme of names and divisions than that which the text presents.

Of Judah. — To Judah (belonged) captains of thousands, namely, the three enumerated in 2 Chronicles 17:14–16: Adnah, Jehohanan, and Amasiah. They were the principal officers, or generals, of the entire forces of Judah.

Adnah the chief — That is, the captain Adnah. That Adnah was commander-in-chief is implied by his being named first, and his corps being the largest.