John Chrysostom

"Wherefore He is able also to save them to the uttermost, that come unto God by Him, seeing He ever liveth to make intercession for them." Thou seest that he says this in respect of that which is according to the flesh. For when He appears as Priest, then He also intercedes. Wherefore also when Paul says, "who also maketh intercession for us," he hints the same thing; the High Priest maketh intercession. …

Homily on Hebrews 13 ↗

Theophylact of Ohrid

Since, he says, He is immortal, He can intercede for all and save to the uttermost, that is, He can grant salvation not temporary, but complete, and naturally, both here and in the life to come. For the high priest in the Old Testament, however illustrious he may have been, offered sacrifices to God during the time he lived, such as Samuel and those like him, but after that no longer, for he died. But here the High Priest is eternal and ever-living. …

Commentary on Hebrews ↗

Oecumenius

"those who come to God." Through the faith that is in Him. For whoever believes in the Son, comes to the Father certainly; for he himself is the way to the Father, and whoever takes hold of this, dwells there. "always living." Therefore, He saves completely, because He always lives. Furthermore, He saves because He intercedes for those who approach God the Father. "to intercede for them." Concerning Christ, as He is according to the flesh, this humble word has been said. …

The Pseudo-Oecumenian Catena on Hebrews ↗

Thomas Aquinas

369. – Then (v. 25) he shows His efficacy. In regard to this he does two things: first, he shows His efficacy; secondly, the mode of His efficacy (v. 25b). 370. – His efficacy lies in the fact that the cause is more potent than its effect; therefore, a temporal cause cannot produce an eternal effect. But Christ's priesthood is eternal; but not the Levitical, as has been proved. Therefore Christ is able to save for all time. …

Commentary on Hebrews ↗