Ancient Israel was meant to be a nation that was holy to God and brought near to him. Everything from the anointing oil, the vessels in the temple, the altar, the laver and so on was designated as holy to God (Exodus 40:9 - 13).
The Temple Courses
The first peculiarity of the time after the days of Moses is how the priests were divided into courses, initially by King David. Such a division existed until captivity. When the captivity ended only 4 of 24 courses came back to serve.
7 - 18 This is the order in which the twenty-four family groups were given their assignments: 1) Jehoiarib; 2) Jedaiah; 3) Harim; 4) Seorim; 5) Malchijah; 6) Mijamin; 7) Hakkoz; 8) Abijah; 9) Jeshua; 10) Shecaniah; 11) Eliashib; 12) Jakim; 13) Huppah; 14) Jeshebeab; 15) Bilgah; 16) Immer; 17) Hezir; 18) Happizzez; 19) Pethahiah; 20) Jehezkel; 21) Jachin; 22) Gamul; 23) Delaiah; 24) Maaziah. (1Chronicles 24)
5. There was in the days of Herod, the king of Judea, a certain priest of the course of Abijah, Zacharias by name; and his wife was of the daughters of Aaron, and her name was Elizabeth.
During the days of King David the Levites had been arranged into 24 courses which were to act as assistants to the priests, provide music, serve as guards and keepers of the gates and act as officers (1Chronicles 23:4, 28, 25:6, 26:6, etc.). These also looked after the sacred vestments and vessels (1Chronicles 23:28 - 32).
Breastplate, Mitre, Phylacteries, Ziz
Of the four distinctive articles in the high priest's dress, the breastplate, alike from its square form and the twelve jewels on it, bearing the names of the tribes, suggest the description of the city of Jerusalem in the book of Revelation (see Revelation 21:16 - 21)
Tradition states priests received their income from offerings made at the temple and elsewhere (Leviticus 7:12, see also 22:29 - 30). Of the ten offerings which might be used throughout the land for their support, five could be given at will to any priest - the tithe of the tithe, the heave-offering of the dough, the first of the fleece and the priest's due of meat (see Numbers 15:20, Deuteronomy 18:3, Romans 11:16). The other five were given to the priests of the special course on duty for the week. Ultimately, however, the high priest had the right to take whatever part of the offerings he decided he wanted.
The officiating priesthood ultimately went away and did not leave behind any of its arrangements (Hebrews 10:1).
17. Therefore, if anyone be in Christ, he is a new creation; the old things have passed away; behold, all things have become new. (2Corinthians 5:17)20. Where Jesus has entered for us as a forerunner, having become a High Priest forever according to the order of Melchisedek. (Hebrews 6:20)