2 Chronicles 35:6

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 Lord by the hand of
Moses;
celebrate the ordinance of the passover in all its rites, according to the law of Moses, at least in every rite in which they were more peculiarly concerned.