Numbers 8:15

Then after that the Levites may go in to serve the Tent of Meeting (tabernacle), but you shall cleanse them [first] and present them as a wave offering;

Numbers 8:11

Aaron shall present the Levites before the Lord as a wave offering from the Israelites, so that they may perform the service of the Lord.

Numbers 8:13

You shall have the Levites stand before Aaron and his sons and present them as a wave offering to the Lord.

Exodus 29:24

and you shall put all these in the hands of Aaron and his sons, and wave them as a wave offering before the Lord.

Numbers 3:12

“Behold, I have taken the Levites from among the sons of Israel instead of and as a substitute for every firstborn, that is, the first that opens the womb among the Israelites. So the Levites shall be Mine,

Numbers 3:23-37

The families of the Gershonites were to camp behind the tabernacle on the west,

Numbers 4:3-32

from thirty years old and upward, even to fifty years old, all who enter the service to do the work in the Tent of Meeting (tabernacle).

1 Chronicles 23:1-32

When David reached old age, he made his son Solomon king over Israel.

1 Chronicles 25:1-26

Moreover, David and the commanders of the army selected for the [temple] service some of the sons of Asaph, Heman, and Jeduthun, who were to prophesy with lyres, harps, and cymbals. The list of the musicians who performed their service was as follows:

Treasury of Scripture Knowledge

Summary

And after that shall the Levites go in to do the service of the tabernacle of the congregation: and thou shalt cleanse them, and offer them for an offering.

Bible References

Go in

Numbers 8:11
Aaron shall present the Levites before the Lord as a wave offering from the Israelites, so that they may perform the service of the Lord.
Numbers 3:23
The families of the Gershonites were to camp behind the tabernacle on the west,
Numbers 4:3
from thirty years old and upward, even to fifty years old, all who enter the service to do the work in the Tent of Meeting (tabernacle).

And offer

Numbers 8:11
Aaron shall present the Levites before the Lord as a wave offering from the Israelites, so that they may perform the service of the Lord.
Numbers 3:12
“Behold, I have taken the Levites from among the sons of Israel instead of and as a substitute for every firstborn, that is, the first that opens the womb among the Israelites. So the Levites shall be Mine,