Ok,
And thou shalt put the mitre upon his head, and put the holy crown upon the mitre. 7 Then shalt thou take the anointing oil, and pour it upon his head, and anoint him.
Ex 29:6-7 (KJV)
Then shalt thou take the anointing oil—It appears, from Isaiah 61:1 that anointing with oil, in consecrating a person to any important office, whether civil or religious, was considered as an emblem of the communication of the gifts and graces of the Holy Spirit. This ceremony was used on three occasions, the installation of prophets, priests, and kings, into their respective offices. But why should such an anointing be deemed necessary? Because the common sense of men taught them that all good, whether spiritual or secular, must come from God, its origin and cause. Hence it was taken for granted,
1. That no man could foretell events unless inspired by the Spirit of God. And therefore the prophet was anointed, to signify the communication of the Spirit of wisdom and knowledge.
2. That no person could offer an acceptable sacrifice to God for the sins of men, or profitably minister in holy things, unless enlightened, influenced, and directed by the Spirit of grace and holiness. Hence the priest was anointed, to signify his being Divinely qualified for the due performance of his sacred functions.
3. That no man could enact just and equitable laws, which should have the prosperity of the community and the welfare of the individual continually in view, or could use the power confided to him only for the suppression of vice and the encouragement of virtue, but that man who was ever under the inspiration of the Almighty.
Kings were inaugurated by anointing with oil. Two of these officers only exist in all civilized nations, the sacerdotal and regal; and in some countries the priest and king are still consecrated by anointing. In the Hebrew language משח mashach signifies to anoint, and משיח mashiach, the anointed person. But as no man was ever dignified by holding the three offices, so no person ever had the title mashiach, the anointed one, but Jesus the Christ. He alone is King of kings and Lord of lords: the king who governs the universe, and rules in the hearts of his followers; the prophet, to instruct men in the way wherein they should go; and the great high priest, to make atonement for their sins. Hence he is called the Messias, a corruption of the word המשיח hammashiach, THE anointed ONE, in Hebrew; which gave birth to ὁ Χριστος, ho Christos, which has precisely the same signification in Greek. Of him, Melchizedek, Abraham, Aaron, David, and others were illustrious types. But none of these had the title of THE MESSIAH, or THE ANOINTED of GOD. This does, and ever will, belong exclusively to JESUS the CHRIST.
—Adam Clarke's Commentary
Not too familiar with the OT but it is starting to make sense...thanks.