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.