2 Chronicles 35:15-17

Young's Literal Translation

¹⁵ And the singers, sons of Asaph, [are] on their station, according to the command of David, and Asaph, and Heman, and Jeduthun seer of the king, and the gate keepers [are] at gate and gate; it is not for them to turn aside from off their service, for their brethren the Levites have prepared for them.

¹⁶ And all the service of Jehovah is prepared on that day, to keep the passover, and to cause to ascend burnt-offering upon the altar of Jehovah, according to the command of king Josiah.

¹⁷ And the sons of Israel who are found make the passover at that time, and the feast of unleavened things, seven days.