Ante-Nicene Fathers, Vol IX:
Epistle to Gregory and Origen's Commentary on the Gospel of John.: Chapter III

3.  In the Spiritual Israel the High-Priests are Those Who Devote Themselves to the Study of Scripture.

But what is the bearing of all this for us?  So you will ask when you read these words, Ambrosius, thou who art truly a man of God, a man in Christ, and who seekest to be not a man only, but a spiritual man. 4459   The bearing is this.  Those of the tribes offer to God, through the levites and priests, tithes and first fruits; not everything which they possess do they regard as tithe or first fruit.  The levites and priests, on the other hand, have no possessions but tithes and first fruits; yet they also in turn offer tithes to God through the high-priests, and, I believe, first fruits too.  The same is the case with those who approach Christian studies.  Most of us devote most of our time to the things of this life, and dedicate to God only a few special acts, thus resembling those members of the tribes who had but few transactions with the priest, and discharged their religious duties with no great expense of time.  But those who devote themselves to the divine word and have no other employment but the service of God may not unnaturally, allowing for the difference of occupation in the two cases, be called our levites and priests.  And those who fulfil a more distinguished office than their kinsmen 4460 will perhaps be high-priests, according to the order of Aaron, not that of Melchisedek.  Here some one may object that it is somewhat too bold to apply the name of high-priests to men, when Jesus Himself is spoken of in many a prophetic passage as the one great priest, as 4461 “We have a great high-priest who has passed through the heavens, Jesus, the Son of God.”  But to this we reply that the Apostle clearly defined his meaning, and declared the prophet to have said about the Christ, “Thou 4462 art a priest for ever, according to the order of Melchisedek,” and not according to the order of Aaron.  We say accordingly that men can be high-priests according to the order of Aaron, but according to the order of Melchisedek only the Christ of God.

Footnotes

1 Cor. ii. 14.

Reading with Neander and Lommatzsch (note), διαφέρον τι for διαφέροντες.

Heb. iv. 14.

Ps. 10:4, Heb. 5:6.  Cf. vii. 11.