1 Chronicles 9:18 - Albert Barnes' Notes on the Bible

Who hitherto waited - Translate, “Who to this day waits. These were the porters in the stations of the sons of Levi.” The words of the first clause refer to Shallum, and imply that, whereas Shallum (or his house) had originally the general superintendence of the temple gates, a change had been made when the author wrote, and Shallum’s charge had become the east gate only. The second clause means; “these were the porters in those fixed stations at the outer gates of the Temple, which corresponded to the camp stations of the Levites who guarded the tabernacle in the early times.”