John Gill's Exposition of the Whole Bible
1 Chronicles 26:12
Among these were the divisions of the porters, even among the chief men,.... These before named were the principal men of the porters, among which was a division or distribution of them into classes or courses, in which they served weekly in turn:
having wards one against another, to minister in the house of the Lord; meaning either to watch in, as on the north against the south, and the east against the west, and "vice versa". The Jews say t, the priests kept ward in three places in the house of the sanctuary; in the house of Abtines, in the house of Nitzotz, and in the house of Moked; and the Levites in twenty one places, five at the five gates of the mountain of the house, four at the four corners of it within, five at the five gates of the court, four at the four corners of it without, one at the chamber of the offering, one at the chamber of the vail, and another behind the house of atonement, the holy of holies; but rather the sense is, that they had wards or courses answerable to those of the priests, and the other Levites, the singers, and were distributed into twenty four classes or courses as they, which are thus reckoned by Kimchi; at the east six, at the north four, at the south four, at Asuppim two and two, which were four, at the west four, and at Parbar two; lo, twenty four; see 1 Chronicles 26:17.
t Misn. Middot, c. 1. sect. 1.