Ezra 6:18-20

Young's Literal Translation

¹⁸ and they have established the priests in their divisions, and the Levites in their courses, over the service of God that [is] in Jerusalem, as it is written in the book of Moses.

¹⁹ And the sons of the captivity make the passover on the fourteenth of the first month,

²⁰ for the priests and the Levites have been purified together -- all of them [are] pure -- and they slaughter the passover for all the sons of the captivity, and for their brethren the priests, and for themselves.