Leviticus 21:5

They shall not make baldness upon their head
For the dead, as Jarchi, Aben Ezra, and Ben Gersom; not shave their heads, or round the corners of them, or make baldness between their eyes on that account; as those things were forbid the Israelites, so the priests also; this and what follow being superstitious customs used among the Heathens in their mournings for the dead, particularly by the Chaldeans, as Aben Ezra observes; and so by the Grecians; when Hephestion, one of Alexander's captains, died, he shaved his soldiers and himself, imitating Achilles in Homer ^F20; so the Egyptians, mourning for the loss of Osiris, annually shaved their heads ^F21; and the priests of Isis, mourning for her lost son, are called by Minutius Felix ^F23 her bald priests; see ( Leviticus 19:27 Leviticus 19:28 ) ( Deuteronomy 14:1 ) ; neither shall they shave off the corner of their beard:
the five corners of it; (See Gill on Leviticus 19:27). This the Israelites in common might not do, and particularly their priests; though the Egyptian priests shaved both their heads and beards, as Herodotus ^F24 relates: and so they are represented in the Table of Isis ^F25: nor make any cuttings in their flesh;
either with their nails, tearing their cheeks and breasts, or with an instrument cutting their flesh in any part of their bodies, as was the custom of Heathen nations; such were made by the Egyptians in their mournings ^F26; (See Gill on Leviticus 19:28).