Charles Ellicott Commentary 1 Chronicles 26:1

"For the courses of the doorkeepers: of the Korahites, Meshelemiah the son of Kore, of the sons of Asaph." — 1 Chronicles 26:1 (ASV)

Concerning the divisions of the porters. —Literally, (as) to courses to porters. (Comp. 1 Chronicles 23:6.) As many as 4,000 Levites were set apart for this function by the king’s orders. (Comp. 1 Chronicles 23:25.)

Of the Korhites was Meshelemiah. — To the Korhites (sons of Korah) belonged Meshelemiah son of Kôrç. Meshelemiah is called Shelemiah (1 Chronicles 26:14), and Shallum (1 Chronicles 9:19).

Of the sons of Asaph. —Not the chief musician Asaph, who was a Gershonite (1 Chronicles 6:39–48); whereas the Korhites were a Kohathite stock (Exodus 6:21). The name here is evidently an abbreviation of Ebiasaph (1 Chronicles 9:19), as Ahaz of Jehoahaz.