Numbers 6:7
They shall not make themselves unclean for their father or for their mother, for their brother or for their sister, when they die because the consecration of their God is upon their head.
Numbers 9:6
And there were certain men, who were defiled by the dead body of a man, that they could not keep the passover on that day; and they came before Moses and before Aaron on that day;
Leviticus 21:1-2
And the LORD said unto Moses, Speak unto the priests, the sons of Aaron, and tell them to not be defiled for the dead among his people.
Leviticus 21:10-12
And he that is the high priest among his brethren, upon whose head the anointing oil was poured and that is consecrated to put on the garments, shall not uncover his head nor rend his clothes;
Ezekiel 44:25
And they shall come near no dead person to defile themselves; but for father, or for mother, or for son, or for daughter, for brother, or for sister that has had no husband, they may defile themselves.