John Chrysostom

Having then suitably accused them, he points out also the manner of their correction. And what is this? "Nevertheless when [one] shall turn to the Lord," which is, to forsake the Law, "the veil is taken away." Seest thou that not over the face of Moses was there that veil, but over the eyesight of the Jews? For it was done, not that the glory of Moses might be hidden, but that the Jews might not see. For they were not capable. So that in them was the deficiency, for it caused not him to be ignorant of any thing, but them. …

Homily 7 on 2 Corinthians ↗

Theophylact of Ohrid

Now he speaks about the way in which the Israelites can be corrected. "When they turn to the Lord," he says, that is, when they abandon the law and approach the spiritual Gospel, then the veil will be removed. For Moses too, as the narrative relates, when he turned to the Lord, removed the veil from himself. …

Commentary on 2 Corinthians ↗

Thomas Aquinas

But when and how that veil shall be removed from them is shown when he says, but when a man turns to the Lord the veil is removed. First he describes how to remove this veil; secondly, the reason for this (v. 17). He says, therefore, that this veil is still upon them; not that the Old Testament is veiled, but because their hearts are veiled. Therefore if it is to be removed, nothing remains but that they be converted. …

Commentary on 2 Corinthians ↗