Yahweh's Original Command Obeyed (Numbers 8:22).
‘And after that went the Levites in to do their service in the tent of meeting before Aaron, and before his sons, as Yahweh had commanded Moses concerning the Levites, so did they to them.'
Once this was accomplished the Levites went in to do their service in the Dwellingplace. This would include ‘policing' the courtyard of the Dwellingplace, assisting some who brought offerings with the slaughter of their sacrifices, generally ministering around inside the courtyard and out, general maintenance of its fabric and appurtenances, preventing those from approaching the Dwellingplace who should not, and being responsible for the Dwellingplace in all its movements.
And all this was done as Yahweh had commanded Moses (see Numbers 8:5-6).
A number of lessons arise for us out of these verses. Firstly the need to be as concerned about minor ministries among God's people as well as the more prominent ones. Secondly a recognition that God is equally concerned about them. Thirdly the need for unity among God's people in making such appointments within the will of God. Fourthly that all, whatever their ministry, regularly need purifying by the blood of Jesus in their ministry and especially at its commencement. It is also a reminder of the need for substitutionary atonement, as the Levites took the place of the firstborn. But how we should rejoice that our substitute before the throne is not the Levites, but our Lord Jesus Christ Himself, Making us sufficient to approach God without fear.