John Chrysostom

What is "the beginning of the doctrine"? He goes on to state it himself, saying, "not laying again" (these are his words) "the foundation of repentance from dead works, and faith toward God, of the doctrine of baptisms and of laying on of hands, of the resurrection of the dead, and of eternal judgment." But if this be "the Beginning," what else is our doctrine save to repent "from dead works," and through the Spirit to receive "the faith," in "the resurrection of the dead, and eternal judgment"? But what is "the Beginning"? …

Homily on Hebrews 9 ↗

Theophylact of Ohrid

Above he said: you have become weak, you have become infants and have reached such a state that you need to learn again the first principles of the faith; therefore now he also says that you must, at last, reason as mature persons and surpass the word of the beginning of Christ, that is, the first principles of the faith, and press on toward "perfection," that is, be receptive to higher things. …

Commentary on Hebrews ↗

Oecumenius

"on to perfection." Having said this, he lets go of the elementary and foundational teachings concerning Christ and is carried towards perfection, not simply referring to the ultimate perfection, but as if to that which is between the elementary teachings of the words of God and the highest perfection. …

The Pseudo-Oecumenian Catena on Hebrews ↗

Thomas Aquinas

275. – Having mentioned the priesthood of Christ according to the order of Melchizedek and scolded the slowness of those to whom he was writing, the Apostle now returns to his theme, in regard to which he does three things: first, he discloses his intention; secondly, its difficulty (v.3); thirdly, he declares his intention (v.9). In regard to the first he does two things: first, he discloses his intention; secondly, he explains what he says (v.1b). 276. …

Commentary on Hebrews ↗