Charles Ellicott Commentary Ezra 6:20

"For the priests and the Levites had purified themselves together; all of them were pure: and they killed the passover for all the children of the captivity, and for their brethren the priests, and for themselves." — Ezra 6:20 (ASV)

Purified together. —This verse should be translated as follows, contrary to the present accentuation: “The priests were purified; and the Levites were purified as one man: all were pure; and killed.” In this fact the present Levitical and official purity of both orders surpassed that of Hezekiah’s celebration (2 Chronicles 29:34; 2 Chronicles 30:3). It had come to be the practice that the Levites slaughtered all the paschal lambs.