John Chrysostom

And therefore he goes on, "But I will come to you shortly, if the Lord will." Now to say this only would seem to be mere threatening. But to promise himself and demand from them the requisite proof by actions also; this was a course for a truly high spirit. Accordingly he added this too, saying, "And I will know, not the word of them which are puffed up, but the power." For not from any excellencies of their own but from their teacher's absence, this self-will arose. Which again itself was a mark of a scornful mind towards him. …

Homily on 1 Corinthians 14 ↗

Theophylact of Ohrid

The Corinthians, relying on eloquence, despised Paul as an unlearned man; therefore he says: I will look not at your eloquence, for it is not what is needed, but at the "power" manifested in signs. For the Kingdom of God was preached and established not by grandeur of speech, but by signs performed through the power of the Holy Spirit.

Commentary on 1 Corinthians ↗

Clement of Alexandria

It teaches the magnificence of the wisdom implanted in her children by instruction. Now the apostle says, "I will know not the speech of those that are puffed up, but the power; for the kingdom of God is not in word." By which is clearly revealed that the gnostic does not sin in speech, nor is puffed up by talk, but is full of work, having made his whole life in accordance with the Lord's commands.

The Stromata Book 7 ↗

Thomas Aquinas

Secondly, he tells them of his visit, when he will come to judge them. First, he foretells his coming when he says: But I will come to you soon. But because in says in Prov (16:9): "The heart of man disposes his way, but the Lord must direct his steps," he adds: If the Lord wills: "If the Lord will and if we shall live, we will do this or that" (Jas 4:5). …

Commentary on 1 Corinthians ↗