Numbers 6:5

6:5 "All the days of his vow of separation there shall no razor come on his head, until the days are fulfilled, in which he separates himself to Yahweh. He shall be holy. He shall let the locks of the hair of his head grow long.
-World English Bible

Other Translation

6:5 All the days of the vow of his separation there shall no rasor come upon his head: until the days be fulfilled, in the which he separateth [himself] unto the LORD, he shall be holy, [and] shall let the locks of the hair of his head grow.
-King James Version