1 Chronicles 9:23

And they and their sons are over the gates of the house of Jehovah, even of the house of the tent, by watches.

1 Chronicles 23:32

And they have kept the charge of the tent of meeting, and the charge of the sanctuary, and the charge of the sons of Aaron, their brethren, for the service of the house of Jehovah.

2 Chronicles 23:19

and he stationeth the gatekeepers over the gates of the house of Jehovah, and the unclean in anything doth not go in.

Nehemiah 12:45

And the singers and the gatekeepers keep the charge of their God, even the charge of the cleansing -- according to the command of David and Solomon his son,

Ezekiel 44:10-11

but -- the Levites who have gone far off from me, in the wandering of Israel when they went astray from Me after their idols, and they have borne their iniquity.

Ezekiel 44:14

and I made them keepers of the charge of the house, for all its service and for all that is done in it.

Treasury of Scripture Knowledge

Summary

So they and their children had the oversight of the gates of the house of the LORD, namely, the house of the tabernacle, by wards.

General references

Bible References

The oversight

1 Chronicles 23:32
And they have kept the charge of the tent of meeting, and the charge of the sanctuary, and the charge of the sons of Aaron, their brethren, for the service of the house of Jehovah.
2 Chronicles 23:19
and he stationeth the gatekeepers over the gates of the house of Jehovah, and the unclean in anything doth not go in.
Nehemiah 12:45
And the singers and the gatekeepers keep the charge of their God, even the charge of the cleansing -- according to the command of David and Solomon his son,
Ezekiel 44:10
but -- the Levites who have gone far off from me, in the wandering of Israel when they went astray from Me after their idols, and they have borne their iniquity.

General references

1 Chronicles 15:23
And Berechiah and Elkanah are gatekeepers for the ark.