'High Priest' in the Bible

Moses then put the breastpiece on Aaron, and he put in the breastpiece the Urim and the Thummim [the sacred articles the high priest used when seeking God’s will concerning the nation].

There shall be no person in the Tent of Meeting when the high priest goes in to make atonement in the Holy Place [within the veil] until he comes out, so that he may make atonement for himself (his own sins) and for his household and for all the congregation of Israel.

Then the Lord said to Moses, “Speak to the priests, the sons of Aaron, and say to them:‘No one shall defile himself [that is, become ceremonially unclean] for the dead among his people [by touching a corpse or assisting in preparing it for burial],

‘But he who is the high priest among his brothers, on whose head the anointing oil has been poured and who has been consecrated to wear the [sacred] garments, shall not uncover his head nor tear his clothes [in mourning],

so that he will not profane or dishonor his children among his people; for I am the Lord who sanctifies the high priest.’”

The bread of the Presence shall be for Aaron and his sons, and they shall eat it in a sacred place, for it is for Aaron a most holy portion of the offerings by fire to the Lord, his portion forever.”