High Priest of Israel
The High Priest of Israel was the head of the kohanim. He played a unique role in the worship conducted in the Tabernacle and later in the Temple in Jerusalem, as well as in some non-ritual matters. Like all priests, he was required to be descended from Aaron, the first priest in the Torah. But unlike other priests, the high priest followed more restrictive laws, wore unique priestly garments, and was the only priest allowed to perform certain ceremonies.
There is still a Samaritan High Priest, but in Judaism, the High Priesthood is defunct.
Titles
The high priest is referred to by a number of titles in the Hebrew Bible; the title kohen gadol did not become dominant until well into the Second Temple period.In addition to the title of "great priest", which later became the standard Hebrew title, the term "head priest" was used, as was "anointed priest". The Torah sometimes uses longer descriptions: "the great priest who was anointed with the holy oil" in Numbers 35:25, "the priest who was anointed and invested to serve in place of his father",in Leviticus 16:32 “the priest who is greater than his brothers, whom oil was poured on his head and who was invested to wear the garments" in Leviticus 21:10, and "the priest in place of him from his sons, who will come to the Tent of Meeting for the holy service" in Exodus 29:30.
Some verses refer by name to a specific individual who is understood to be "the" priest, i.e. the high priest at that moment.
Hebrew Bible
Individuals
The first high priest was Aaron himself, the ancestor of all priests; he was appointed to this role by Yahweh according to Exodus 28:1–2 and 29:4–5.Other notable high priests in the Bible include Aaron's son Eleazar, Eleazar's son Phinehas, Eli, and Zadok.
After the Babylonian captivity, the first high priest was Joshua the High Priest, who is mentioned as a prominent leader alongside the political ruler Zerubbabel. Joshua was Tzadokite according to 1 Chronicles 5:38-40 and Haggai 2:2 in accordance with Ezekiel's prophecy.
It was presumed that the high priest's son would succeed him, but this did not always happen. The role eventually passed from Phinehas to Eli, who was descended from Ithamar, brother of Eleazar. However, Eli's family eventually lost rights to the high priesthood due to their sin in 1 Samuel 2:27-35, a prophecy fulfilled when Solomon appointed Zadok, a descendant of Eleazar, in place of Abiathar, a descendant of Eli, according to 1 Kings 2:35 and 1 Chronicles 24:2–3.
Rabbinic Judaism supports the positions that Ezra was an ordinary member of the priesthood and that he actually served as a high priest.
Roles
The distinguished rank of the high priest is apparent from the fact that his sins are regarded as belonging also to the people. He was entrusted with the Urim and Thummim, which were worn in his garments.On Yom Kippur, he alone performed the Yom Kippur Temple service, entering the Holy of Holies in the Temple in Jerusalem to atone for himself and for the people. Only he could offer the sacrifices for the sins of the entire people in Leviticus 4:16. He also offered a meal-offering twice daily, on behalf of himself and the whole priesthood in Leviticus 6:13-15, though the wording of the law is not altogether definite. An unintentional killer was required to remain in one of the Cities of Refuge until the death of the high priest, at which point the killer could return home in Numbers 35:25, 28, 32.
Qualifications
The high priest alone was anointed with holy anointing oil upon his consecration, hence the title of the "anointed priest". The consecration also required wearing the special high priestly vestments for seven days.He was permitted to marry only an Israelite virgin.
He was required to strictly avoid ritual defilement. He was forbidden to come in contact with the bodies of the dead, not even those of his parents, according to Leviticus 21:11, unlike regular priests, who may become ritually impure for the death of an immediate relative according to Leviticus 21:1-3. He was also forbidden to leave his hair dishevelled or exposed, or to rend his garments as signs of mourning per Leviticus 21:10.
Vestments
The Torah provides for specific vestments to be worn by the priests when they are ministering in the Tabernacle. The high priest wore eight special garments. Of these, four were of the same type worn by all priests, and four were unique to the high priest.Those vestments which were common to all priests were the priestly tunic, priestly sash, priestly turban, and priestly undergarments.
The vestments that were unique to the high priest were the priestly robe, ephod, priestly breastplate, and priestly golden head plate. In addition to the above "golden garments", he also had a set of white "linen garments", which he wore only for the Yom Kippur Temple service.
In rabbinic literature
Even though Aaron was the first high priest mentioned in the Book of Exodus, Louis Ginzberg in Legends of the Jews noted that in legends the first man that assumed the title of high priest of God is Enoch, who was succeeded by Methuselah, Lamech, Noah, Shem, Melchizedek, Abraham, Isaac and Levi.The high priest is the chief of all the priests; he should be anointed and invested with the priestly garments; but if the sacred oil were not obtainable, investiture with the additional four garments is regarded as sufficient. A high priest so invested is known as merubbeh begadim. This investiture consists of arraying him in the eight pieces of dress and in removing them again on eight successive days, though the investiture on the first day suffices to qualify him for the functions of the office. The only distinction between the "anointed" and the "invested" high priest is that the former offers the bull for an unintentional transgression.
The age of eligibility for the office is not fixed in the Torah; but according to rabbinical tradition it was twenty. Aristobulus, however, was only seventeen when appointed by Herod the Great; but the son of Onias III was too young to succeed his father.
Legitimacy of birth and lineage was essential, hence the care in keeping genealogical records and distrust of one whose mother had been captured in war. According to Josephus, birth on foreign soil was no disqualification.
The high priest, like all priests, would minister barefoot when he was serving in the Temple. Like all priests, he had to immerse himself in the mikvah before vesting, and wash his hands and his feet before performing any sacred act. Neither common nor high priests could serve unless they wore their priestly vestments. It is further taught that just as the sacrifices facilitate an atonement for sin, so do the priestly garments.
Though other priests would serve only when it was their week on rotation and on festivals, the high priest could choose to perform any priestly rite at any time. Josephus contends that the high priest almost invariably participated in the ceremonies on Shabbat, Rosh Chodesh, and the three festivals. This may also be inferred from the glowing description given in the Wisdom of Sirach 1 of the high priest's appearance at the altar.
Powers
The Great Sanhedrin alone had the right to appoint, or confirm the appointment of, the high priest. His consecration could take place only in the daytime. Two high priests could not be appointed together. Every high priest had a deputy—called the segan, mishneh, or "memunneh" —to stand at his right; another assistant was called the "Catholicos".For offenses which entailed flagellation, the high priest could be sentenced by a court of three; after submitting to the penalty, he could resume his office. The high priest was expected to be superior to all other priests in physique, in wisdom, in dignity, and in material wealth; if he was poor, his brother priests contributed to make him rich; but none of these conditions was indispensable.
The high priest was required to be mindful of his honor. He was not allowed to mingle with the common people, nor permit himself to be seen disrobed, or in a public bath, etc.; but he could invite others to bathe with him. He was not allowed to participate in a public banquet, but he could pay a visit of consolation to mourners, though even then, his dignity was guarded by prescribed etiquette.
Restrictions
The high priest was not allowed to follow the bier of one in his own family who had died, nor leave the Temple or his house during the time of mourning. The people visited him to offer consolation; in receiving them, the Segan was at his right, the next in rank and the people at his left. The people said: "We are thy atonement." He answered: "Be ye blessed from heaven". During the offering of consolation he sat on a stool, the people on the floor; he rent his garments, not from above, but from below, near the feet, the penalty for rending them from above being flagellation. He could not permit his hair to be disheveled, nor could he cut it. He had one house attached to the Temple, and another in the city of Jerusalem. His honor required that he should spend most of his time in the Sanctuary, The high priest was subject to the jurisdiction of the courts, but if accused of a crime entailing capital punishment he was tried by the Great Sanhedrin; he could, however, refuse to give testimony.The high priest needed to be married, and "should only marry a virgin"; to guard against contingencies, it was proposed to hold a second wife in readiness immediately before Yom Kippur; but he was to have only one wife at a time. He could perform halizah, and it could be given to his widow, as she also was subject to the Levirate; his divorced wife could marry again. When entering the Temple, he was supported to the curtain by three men. He could take part in the service whenever he desired. On Yom Kippur, he wore white garments, while on other occasions he wore his golden vestments. The seven days preceding Yom Kippur were devoted to preparing for his high function, precautions being taken to prevent any accident that might render him Levitically impure. The ceremonial for that day is described in detail in Mishnah Yoma.