Ezra 6:20

For the priests and Levites were purified as one, all of them being purified; and they will slaughter the pass-over for all the sons of the exile, and for their brethren the priests, and for themselves.

2 Chronicles 35:11

And they will slaughter the passover, and the priests will sprinkle from their hand, and the Levites flaying.

2 Chronicles 29:34

Only the priests were for fewness and they could not slaughter all the burnt-offerings: and their brethren the Levites will strengthen them till the finishing of the work, and till the priests shall consecrate themselves: for the Levites being upright of heart to consecrate themselves more than the priests.

Exodus 12:21

And Moses will call for all the old men of Israel and he will say to them, Draw out and take to yourselves a sheep according to your tribes, and slaughter the passing over.

2 Chronicles 30:15-17

They will slaughter the passover in the fourteenth to the second month: and the priests and the Levites were ashamed, and they will consecrate themselves and bring burnt-offerings to the house of Jehovah.

Hebrews 7:27

Who has no necessity according to the day, as the chief priests, before to bring up sacrifices for their own sins, then for those of the people; for this he did once, having brought up himself.

Treasury of Scripture Knowledge

Summary

For the priests and the Levites were purified together, all of them were pure, and killed the passover for all the children of the captivity, and for their brethren the priests, and for themselves.

Bible References

Purified together

2 Chronicles 29:34
Only the priests were for fewness and they could not slaughter all the burnt-offerings: and their brethren the Levites will strengthen them till the finishing of the work, and till the priests shall consecrate themselves: for the Levites being upright of heart to consecrate themselves more than the priests.
2 Chronicles 30:15
They will slaughter the passover in the fourteenth to the second month: and the priests and the Levites were ashamed, and they will consecrate themselves and bring burnt-offerings to the house of Jehovah.

Killed

Exodus 12:21
And Moses will call for all the old men of Israel and he will say to them, Draw out and take to yourselves a sheep according to your tribes, and slaughter the passing over.
2 Chronicles 35:11
And they will slaughter the passover, and the priests will sprinkle from their hand, and the Levites flaying.
Hebrews 7:27
Who has no necessity according to the day, as the chief priests, before to bring up sacrifices for their own sins, then for those of the people; for this he did once, having brought up himself.