Numbers 8:20

18 And I have taken the Levites for all the firstborn of the children of Israel.

19 And I have given the Levites as a gift to Aaron and to his sons from among the children of Israel, to do the service of the children of Israel in the tabernacle of the congregation, and to make an atonement for the children of Israel: that there be no plague among the children of Israel, when the children of Israel come nigh unto the sanctuary.

And Moses, and Aaron, and all the congregation of the children of Israel, did to the Levites according unto all that the LORD commanded Moses concerning the Levites, so did the children of Israel unto them.

21 And the Levites were purified, and they washed their clothes; and Aaron offered them as an offering before the LORD; and Aaron made an atonement for them to cleanse them.

22 And after that went the Levites in to do their service in the tabernacle of the congregation before Aaron, and before his sons: as the LORD had commanded Moses concerning the Levites, so did they unto them.

This was said to Israel at a particular time, so it is wise to read it together with the surrounding text. Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB
So Moses, Aaron, and the whole congregation of Israel did with the Levites everything that the LORD had commanded Moses they should do.
KJV
And Moses, and Aaron, and all the congregation of the children of Israel, did to the Levites according unto all that the LORD commanded Moses concerning the Levites, so did the children of Israel unto them.
WEB
Moses, and Aaron, and all the congregation of the children of Israel did so to the Levites. According to all that the LORD commanded Moses concerning the Levites, so the children of Israel did to them.
ASV
Thus did Moses, and Aaron, and all the congregation of the children of Israel, unto the Levites: according unto all that Jehovah commanded Moses touching the Levites, so did the children of Israel unto them.
DARBY
And Moses and Aaron, and all the assembly of the children of Israel, did to the Levites according to all that Jehovah had commanded Moses concerning the Levites: so did the children of Israel to them.
BLB
And Moses and Aaron and all the congregation of the sons of Israel did to the Levites according to all that YHWH commanded Moses concerning the Levites; so the sons of Israel did to them.
ÅB
Og Moses og Aron og hele Israels barns menighet gjorde slik med levittene; aldeles som Herren hadde befalt Moses om levittene, slik gjorde Israels barn med dem.
OTB
Moses, Aron og hele den israelittiske menigheten gjorde med levittene akkurat som Herren hadde befalt Moses.
B1930
Og Moses og Aron og hele Israels barns menighet gjorde således med levittene; aldeles som Herren hadde befalt Moses om levittene, således gjorde Israels barn med dem.

Study notes (Tyndale)

Original text and word study