Numbers 6:7
he shall not make himself unclean at the death of his father, mother, brother or sister: For the abstinence of his God is upon his head.
Numbers 9:6
And it chanced that certain men which were defiled with a dead corpse, that they might not offer Passover the same day, came before Moses and Aaron the same day,
Leviticus 21:1-2
And the LORD said unto Moses, "Speak unto the priests the sons of Aaron and say unto them, 'A priest shall defile himself at the death of none of his people,
Leviticus 21:10-12
He that is the high priest among his brethren, upon whose head the anointing oil was poured and whose hand was filled to put on the vestments, shall not uncover his head nor rent his clothes,
Ezekiel 44:25
They shall come at no dead person, to defile themselves; except it be father or mother, son or daughter, brother or sister that hath had yet no husband: in such they may be defiled.