Specifically, this kohanic settlement region stretched from the Beit Netofa Valley, through the Nazareth region to Arbel and the vicinity of Tiberias.
In subsequent years, there was a custom of publicly recalling every Sabbath in the synagogues the courses of the priests, a practice that reinforced the prestige of the priests' lineage.
During the existence of the Temple in Jerusalem, kohanim performed the daily and holiday (Yom Tov) duties of sacrificial offerings.
The term is used colloquially in Orthodox Judaism in reference to modern day descendants of Aharon.
The noun kohen is used in the Torah to refer to priests, whether Jewish or pagan, such as the kohanim ("priests") of Baal (2 Kings ) or Dagon, though Christian priests are referred to in Hebrew by the term komer ().
Ethiopian Jewish religious leaders are sometimes called kahen, a form of the same word, but the position is not hereditary and their duties are more like those of rabbis than kohanim in most Jewish communities.
In every generation when the Temple was standing, one kohen would be singled out to perform the functions of the High Priest (Hebrew kohen gadol). Another unique task of the high priest was the offering of a daily meal sacrifice; he also held the prerogative to supersede any priest and offer any offering he chose.
Each of the 24 groups consisted of six priestly families, with each of the six serving one day of the week. According to later rabbinical interpretation, these 24 groups changed every Sabbath at the completion of the Mussaf service.
Professor Yosef Tobi, describing a stone inscription found in Yemen and which contains a partial list of the names (in Hebrew) of the twenty-four priestly courses and their places of residence, writes: “As for the probable strong spiritual attachment held by the Jews of Ḥimyar for the Land of Israel, this is also attested to by an inscription bearing the names of the miśmarōṯ (priestly wards), which was initially discovered in September 1970 by W. Grjaznevitch within a mosque in Bayt al-Ḥāḍir, a village situated near Tan‘im, east of Ṣanʻā’.
This inscription has been published by several European scholars, but the seminal study was carried out by E. Urbach (1973), one of the most important scholars of rabbinic literature in the previous generation.
The second is Potiphera, priest of Heliopolis, then Jethro, priest of Midian both pagan priests of their era.
The Torah mentions Melchizedek king of Salem, identified by Rashi as being Shem the son of Noah, as a "priest" kohen to El Elyon (the supreme God) Genesis .