1 Chronicles 9:22-24

22All those chosen to be gatekeepers at the thresholds were 212. They were enrolled by their genealogies in their villages [around Jerusalem], these men [whose grandfathers] David and Samuel the seer had appointed to their official duty.

23So they and their sons were in charge of the gates of the house of the Lord, that is, the house of the tabernacle, as guards.

24The gatekeepers were stationed on the four sides —on the east, west, north, and south.