Numbers 9:7
"And those men said unto him, We are defiled by the dead body of a man: wherefore are we kept back, that we may not offer an offering of the LORD in his appointed season among the children of Israel?"
Cross References (ranked by relevance)
Deuteronomy 16:2
Thou shalt therefore sacrifice the passover unto the LORD thy God, of the flock and the herd, in the place which the LORD shall choose to place his name there.
Numbers 9:2
Let the children of Israel also keep the passover at his appointed season.
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. And the people bowed the head and worshipped.