Leviticus 21:1-5

Pretty stringent standards. But, again—do not let this get far from your mind—God is going to want us to reflect His holiness as much as we possibly can, even as He wanted His holiness reflected in these physical areas by these people.

These are things the pagans did as part of their practices, and no one who is a priest serving God is to imitate in any way shape or form anything that the pagans do. You are beginning to see that He is touching on looks, He is touching on hair, He is touching on the way they take care of their face and other parts of their body. They are to make no cuttings, and I would imagine, too, that this would cover things like tattoos. People have been doing that for thousands of years. God considers that a defacing of the gift of our body that He has given us. It does not make God holy to see us defacing ourselves.