Passage cross-references.

And they killed the passover, and the priests sprinkled the blood from their hands, and the Levites flayed them.

For they could not keep it at that time, because the priests had not sanctified themselves sufficiently, neither had the people gathered themselves together to Jerusalem.

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.

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 they shall keep thy charge, and the charge of all the tabernacle: only they shall not come nigh the vessels of the sanctuary and the altar, that neither they, nor ye also, die.

And I, behold, I have taken your brethren the Levites from among the children of Israel: to you they are given as a gift for the LORD, to do the service of the tabernacle of the congregation. …

I know also, my God, that thou triest the heart, and hast pleasure in uprightness. As for me, in the uprightness of mine heart I have willingly offered all these things: and now have I seen with joy thy people, which are present here, to offer willingly unto thee.

And said unto them, Hear me, ye Levites, sanctify now yourselves, and sanctify the house of the LORD God of your fathers, and carry forth the filthiness out of the holy place.

And they stood in their place after their manner, according to the law of Moses the man of God: the priests sprinkled the blood, which they received of the hand of the Levites. …

My defence is of God, which saveth the upright in heart.

I will wash mine hands in innocency: so will I compass thine altar, O LORD:

But judgment shall return unto righteousness: and all the upright in heart shall follow it.