That you 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. And the people bowed the head and worshiped.
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George Leo Haydock
Victim, sacrificed upon the altar, in honour of the passage It was a true "sacrifice of propitiation "as the Arabic translates, and of thanksgiving. (Calmet)