'Thresholds' in the Bible

Shallum son of Kore, son of Ebiasaph, son of Korah and his relatives from his ancestral household, the Korahites, were assigned to guard the thresholds of the tent. Their ancestors had been assigned to the Lord’s camp as guardians of the entrance.

The total number of those chosen to be gatekeepers at the thresholds was 212. They were registered by genealogy in their villages. David and Samuel the seer had appointed them to their trusted positions.