Adam Clarke on 1 Chronicles 26:1

The divisions of the porters - There were four classes of these, each of which belonged to one of the four gates of the temple, which opened to the four cardinal points of heaven. The eastern gate fell to Shelemiah; the northern, to Zechariah, 1Chr 26:14; the southern, to Obed-edom, 1Chr 26:15; the western, to Shuppim and Hosah, 1Chr 26:16. These several persons were captains of these porter-bands or door-keepers at the different gates. There were probably a thousand men under each of these captains; as we find, from 1Chr 23:5, that there were four thousand in all.