2 Chronicles 23:4

This is what you are to do: a third of you, priests and Levites who are coming on duty on the Sabbath, are to be gatekeepers.

1 Chronicles 9:25

Their relatives came from their villages at fixed times to be with them seven days,

1 Chronicles 23:3-6

The Levites 30 years old or more were counted; the total number of men was 38,000 by headcount.

1 Chronicles 24:3-6

Together with Zadok from the sons of Eleazar and Ahimelech from the sons of Ithamar, David divided them according to the assigned duties of their service.

1 Chronicles 26:13-16

They cast lots for each gate according to their ancestral houses, young and old alike.

Luke 1:8-9

When his division was on duty and he was serving as priest before God,

Treasury of Scripture Knowledge

Summary

This is the thing that ye shall do; A third part of you entering on the sabbath, of the priests and of the Levites, shall be porters of the doors;

Bible References

Entering

1 Chronicles 23:3
The Levites 30 years old or more were counted; the total number of men was 38,000 by headcount.
1 Chronicles 24:3
Together with Zadok from the sons of Eleazar and Ahimelech from the sons of Ithamar, David divided them according to the assigned duties of their service.
Luke 1:8
When his division was on duty and he was serving as priest before God,

Porters

1 Chronicles 26:13
They cast lots for each gate according to their ancestral houses, young and old alike.

Holman Christian Standard Bible®, Copyright © 1999, 2000, 2002, 2003, 2009 by Holman Bible Publishers.