John Chrysostom

"But the word of the oath which was since the Law maketh the Son who has been consecrated for evermore." "Consecrated": what is that? Paul does not set down the common terms of contradistinction; for after saying "having Infirmity," he did not say "the Son" who is mighty, but "consecrated": i.e. mighty, as one might say. Thou seest that the name Son is used in contradistinction to that of servant. And by "infirmity" he means either sin or death. What is, "for evermore"? Not now only without sin but always. …

Homily on Hebrews 13 ↗

Theophylact of Ohrid

Lest you think that although He offered once, yet it was also for Himself, he now proves that He did not offer for His own sins. For "the law appoints as high priests" ordinary men "who have weaknesses," that is, those who cannot resist sin, but who themselves, being weak, are subject to falls. But He, as the Son, being so powerful, how could He have sin? And having no sin, why would He offer a sacrifice for Himself? …

Commentary on Hebrews ↗

Oecumenius

"For the law appoints men."And for whose sake did he not need, he says, to offer a sacrifice for himself? Nor did he often offer for the people, as the high priests do, but having offered once, he was sufficient; why? Because the priests who are appointed from the law are under sin. Therefore, they must always offer a sacrifice for both themselves and the people. …

The Pseudo-Oecumenian Catena on Hebrews ↗