Numbers 6:6-8

American Standard Version

⁶ All the days that he separateth himself unto Jehovah he shall not come near to a dead body. ⁷ He shall not make himself unclean for his father, or for his mother, for his brother, or for his sister, when they die; because his separation unto God is upon his head. ⁸ All the days of his separation he is holy unto Jehovah.