John Gill Commentary 1 Chronicles 26:17

"Eastward were six Levites, northward four a day, southward four a day, and for the store-house two and two." — 1 Chronicles 26:17 (ASV)

Eastward were six Levites
The eastern gate, being the way of entrance into the temple, required more porters:

northward four a day ;
in the daytime, or every day, where was the gate Teri or Tedi, (1 Chronicles 26:14) , southward four a day: at the two gates of Huldah, (1 Chronicles 26:15) and toward Asuppim two and two; which were two gates, two at each gate, (1 Chronicles 26:15) .