Theophylact of Ohrid

Not simply pure, but "glorious"! And just as Christ is the source of all blessings for the Church, so you too be the same for your wife; and just as He imparted spiritual beauty to the Church, so you too strive for this, and not for bodily beauty. And if you seek spiritual beauty in your wife, you will soon create it in her, setting her in order and making her glorious in spirit both for yourself and for God. These words refer to the passions of the soul. …

Commentary on Ephesians ↗

Augustine of Hippo

For in this sense must be understood that which the apostle whom we have so often quoted says elsewhere: "Christ loved the Church, and gave Himself for it; that He might sanctify and cleanse it by the washing of water by the word that He might present it to Himself a glorious Church, not having spot, or wrinkle, or any such thing." It must, I say, be understood as implying, that by this laver of regeneration and word of sanctification all the evils of regenerate men of whatever kind are cleansed and healed,—not the sins only which …

On Marriage And Concupiscence 1.38 ↗

Thomas Aquinas

The goal of this sanctifying action is the Church's purity. Thus he states that he might present it to himself, a glorious church; as if the Apostle said: It would be highly improper for the immaculate bridegroom to wed a soiled bride. This is why he presents her to himself in an immaculate state, now through grace and in the future through glory. Regarding the latter, he says glorious by the clarity of both body and soul. For "he will reform the body of our lowness, made like to the body of his glory" (Phil. 3:21). …

Commentary on Ephesians ↗