Slaughter the Passover lambs, consecrate yourselves, and make preparations for your fellow countrymen to carry out the word of the LORD given by Moses.”
The destruction which Josiah made of idols and idolatry was more largely related in the Kings, but just mentioned here in the foregoing chapter (v. 33); but his solemnizing the passover, which was touched upon there (Kg2 23:21), is very particularly related here. Many were the feasts of the Lord, appointed by the ceremonial law, but the passover was the chief.
Commenting on 2 Chronicles 35:1-19
So kill the passover,.... In the manner, time, and place, and for the persons it should be killed: and sanctify yourselves: by washing themselves and garments, that they might be fit for this service: and prepare your brethren; prepare a lamb for your brethren, or instruct them how to perform their office that needed instruction: that they may do according to the word of the...
So kill the passover, &c.--The design of the minute directions given here was to facilitate the distribution of the paschal lambs. These were to be eaten by the respective families according to their numbers (Exo 12:3). But multitudes of the people, especially those from Israel, having been reduced to poverty through the Assyrian devastations, were to be provided with the means of commemorating the passover.