John Chrysostom

"I will most gladly spend and be spent for your souls." 'For the law of nature indeed has commanded the parents to lay up for the children; but I do not do this only, but I give myself also besides.' And this lavishness of his, the not only not receiving, but giving also besides, is not in common sort but accompanied with great liberality, and out of his own want; for the words, "I will be spent," are of one who would imply this. …

Homily 27 on 2 Corinthians ↗

Theophylact of Ohrid

I, he says, not only will take nothing from you, but rather will give to you, for such is the meaning of the word "spend." And why do I say "spend" money? I myself "will be spent," that is, if for the salvation of your souls I need to lose my body, I will not spare it. In these words is expressed both condemnation and love. I do this, he says, for the sake of those loved by me, but who do not love me in return. …

Commentary on 2 Corinthians ↗

Thomas Aquinas

Then he applies the simile, in which he proposed two things: one is that the children should not lay up for the parents, and this is now clear. The other is that parents should lay up for and give to the children; in regard to this he says: therefore, because I am your father, I am ready to give to you, and this is what he says: I will most gladly spend good things on you, not only spiritual goods by preaching and giving examples, but even temporal goods, which he did, inasmuch as he preached to them and served them with the revenues …

Commentary on 2 Corinthians ↗