The garments of the priests and high priests are described, and prescribed, in detail in Leviticus. In addition, they would engage in many different rituals, such as the priestly blessing, the red heifer, the redemption of the firstborn, and various purification rituals. The priests were to officiate at many offerings under the Law of Moses, including the burnt offering, meal offering, dough offering, sin offering, guilt offering, release of the scapegoat, peace offering, heave offering, drink offering, incense offering, thank offering, etc., throughout the liturgical year. The first mention of a priesthood occurs in Exodus 40:15 'And thou shalt anoint them, as thou didst anoint their father, that they may minister unto me in the priest's office: for their anointing shall surely be an everlasting priesthood throughout their generations.' (KJV, 1611) Among these priests a High Priest was anointed (first mentioned Leviticus 21:10), to serve in unique functions, such as entering the Holy of Holies once yearly on the Day of Atonement. The third priest to be mentioned is Jethro, priest of Midian, and Moses' father in law. The first priest mentioned of another god is Potipherah priest of On, whose daughter Asenath married Joseph in Egypt. The first priest mentioned in the Bible is Melchizedek, who was a priest of the Most High. Illustration of Aaron's lineage from the 1493 Nuremberg Chronicle.

Who are the priests in the bible