Numbers 6:7
He is not to defile himself on account of his father, mother, brother, and sister when they die, because the crown of his consecration to God is on his head.
Numbers 9:6
But there were men who couldn't observe the Passover that day because they had come in contact with a corpse. That very day, they approached Moses and Aaron
Leviticus 21:1-2
The LORD told Moses, "Speak to the priests, Aaron's sons, and tell them that no priest is to defile himself on account of the dead among his people,
Leviticus 21:10-12
"The high priest among his relatives whose head has been anointed with oil and who has been consecrated to put on the priestly clothing is not to let his hair hang loose or to tear his clothes.
Ezekiel 44:25
They are not to come in contact with a dead body, so they don't defile themselves, except in the case of their father, mother, son, daughter, brother, or for an unmarried sister, on whose behalf they may defile themselves.