Leviticus 21:10-11

¹⁰And the priest that is highest among his brethren, upon whose head the anointing oil hath been poured, and who hath been consecrated to put on the garments, shall not let the hair of his head grow long, and his garments shall he not rend;

¹¹Neither shall he go in to any dead body; even on his father, and on his mother shall he not defile himself.