Numbers 6:5-7

American Standard Version

⁵ All the days of his vow of separation there shall no razor come upon his head: until the days be fulfilled, in which he separateth himself unto Jehovah, he shall be holy; he shall let the locks of the hair of his head grow long.

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.