John Chrysostom

"As having nothing, and yet possessing all things." And how can this be? Yea rather, how can the opposite be? For he that possesseth many things hath nothing; and he that hath nothing possesseth the goods of all. And not here only, but also in the other points, contraries were to have all things, let us bring forth this man himself into the midst, who commanded the world and was lord not only of their substance, but of their very eyes even. "If possible," he says, "ye would have plucked out your eyes, and have given them to me."

Homily 12 on 2 Corinthians ↗

Theophylact of Ohrid

"They grieve us, yet we are always rejoicing": though in outward appearance, he says, we seem to be grieving, we enjoy the most perfect joy; for it is not the case that we sometimes rejoice and sometimes do not, but we always rejoice. "We are poor, yet we enrich many": the Apostle enriched many with both spiritual and material wealth. For, having the homes of all open to him, he was the wealthiest and was able to bestow upon and feed others, such as, for example, the saints in Jerusalem. He shows the same thing further on as well. …

Commentary on 2 Corinthians ↗

Clement of Alexandria

But there is that species of knowledge which is characteristic of the herald, and that which is, as it were, characteristic of a messenger, and it is serviceable in whatever way it operates, both by the hand and tongue. "For he that soweth to the Spirit, shall of the Spirit reap life everlasting. …

The Stromata Book 1 ↗

Augustine of Hippo

It could happen that some public official would say to a Christian: "Either you will stop being a Christian, or, if you persist in being one, you shall have no house or property." That will be the time when those rich men, who had decided to keep their riches in order to win merit with God by using them for good works, will choose to give them up for Christ's sake rather than Christ for their sake.… Thus they become as men "having nothing, yet possessing all things"— and everlasting life in the world to come, lest by giving up Christ …

Letter 157, To Hilarius ↗

Thomas Aquinas

Then he discusses the things which pertain to the concupiscence of the eyes, and in regard to this he mentions two things. One of these is in relation to others, and according to this the right hand in riches consists in a man abounding, so that he can minister to others from his riches. But the left hand consists in a man's being so poor that he must beg from others. Hence he says that in these temporal things we are as poor, i.e., receiving from others; but as to spiritual things, yet making many rich. …

Commentary on 2 Corinthians ↗