Thematic Bible: Their posts were determined by lot

These also cast lots just as their relatives the sons of Aaron in the presence of David the king, Zadok, Ahimelech, and the heads of the fathers’ households of the priests and of the Levites—the head of fathers’ households as well as those of his younger brother.

They cast lots, the small and the great alike, according to their fathers' households, for every gate. The lot to the east fell to Shelemiah. Then they cast lots for his son Zechariah, a counselor with insight, and his lot came out to the north. For Obed-edom it fell to the south, and to his sons went the storehouse. read more.
For Shuppim and Hosah it was to the west, by the gate of Shallecheth, on the ascending highway. Guard corresponded to guard. On the east there were six Levites, on the north four daily, on the south four daily, and at the storehouse two by two. At the Parbar on the west there were four at the highway and two at the Parbar. These were the divisions of the gatekeepers of the sons of Korah and of the sons of Merari.