Keil & Delitzsch, on 1Chr 9:19

“But Sellum the son of Core, the son of Abiasaph, the son of Core, with his brethren and his father’s house, the Corites were over the works of the service, keepers of the gates of the tabernacle: and their families in turns were keepers of the entrance of the camp of the Lord.”

“And Zechariah the son of Meshelemiah,.... Some think this refers to one that was in the times of David; but it seems rather to respect one that was after the Babylonish captivity, see Ch1 26:1 though he and his brethren were in an office established in the times of David, and the order of which was now, as then, observed: was porter of the door of the tabernacle of the congregation: who was the chief porter, and kept the door; either that led into the outer court, and kept out all unclean persons from entering there; or that which led into the court of the priests, that none but priests might enter there.”

Imported from an open dataset — not yet checked against the printed edition.