Exodus 12:27

that ye shall say, It is the sacrifice of the Lord's Passover, who passed over the houses of the children of Israel in Egypt when He smote the Egyptians and delivered our houses. Note that religious observances should not be performed in a mechanical manner, but with a proper understanding of their origin and their meaning. And the people bowed the head and worshiped. They accepted the words of the Lord in grateful adoration.