Albert Barnes Commentary 1 Chronicles 27:2

"Over the first course for the first month was Jashobeam the son of Zabdiel: and in his course were twenty and four thousand." — 1 Chronicles 27:2 (ASV)

Jashobeam - Jashobeam is mentioned in marginal references as the chief of David’s mighty men. He is called in 1 Chronicles 11:11 the son of Hachmoni. We learn from 1 Chronicles 27:3 that he was of the tribe of Judah, being descended from Perez (or Pharez), the son of Judah, from whom David himself was descended. See 1 Chronicles 2:3–15.