The priesthood of ancient Israel was the class of male individuals, who, according to the Hebrew Bible, were patrilineal descendants from Aaron (the elder brother of Moses), who served in the Tabernacle, Solomon's Temple and Second Temple until the destruction of Jerusalem in 70 CE. Their temple role included animal sacrifice. The priests (Hebrew kohanim) are viewed as continuing in the Kohen families of rabbinical Judaism.
The first priest mentioned in the Bible is Melchizedek, who was a priest of the Most High, and who officiated for Abraham[clarification needed]. The first priest mentioned of another god is Potipherah priest of On, whose daughter Asenath married Joseph in Egypt. The third priest to be mentioned is Jethro, priest of Midian, and Moses' father in law. The first mention of a priesthood occurs in Exodus 40:15 "And thou shalt anoint them, as thou didst anoint their father [Aaron], 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 priests were to officiate at many offerings under the Law of Moses, including the passover sacrifice, sin offering, guilt offering, release of the scapegoat, burnt offering, peace offering, heave offering, meal offering, dough offering, drink offering, incense offering, thank offering, etc., throughout the liturgical year. As well, 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 garments of the priests and high priests are described, and proscribed, in detail in Leviticus. For the high priest these include a priestly tunic, linen undergarments, sash, robe, priestly turban, ephod (with Urim and Thummim), and a priestly breastplate with 12 stones representing the twelve tribes of Israel.
The priests served in rotating priestly divisions.
The starting point of much critical scholarship of the priesthood in ancient Israel is the thesis of Julius Wellhausen that Israel's history is redacted and represents three stages; (1) non Levitical priests, (2) Levitical priests, (3) Aaronids and Levites. However Wellhausen's views depend on some critical, but unproven, assumptions, and some scholars consider that the study of the cult and priesthood of ancient Israel is still in its infancy compared to other areas of biblical studies.