John Chrysostom

"To speak after the manner of men" means to use human examples. Having founded his argument on the Scriptures, on the miracles wrought among themselves, on the sufferings of Christ, and on the Patriarch, he proceeds to common usages; and this he does invariably, in order to sweeten his discourse, and render it more acceptable and intelligible to the duller sort. Thus he argues with the Corinthians, "Who feedeth a flock, and eateth not of the milk of the flock? …

Homily on Galatians 3 ↗

Theophylact of Ohrid

He called them foolish above, but now he calls them brothers—there restraining, and here consoling. I am going to present you, he says, a human example. Paul wants to show that faith is a covenant more ancient than the law, and that it would be unjust to prefer the law over it. He brought an example to illustrate this. If, he says, a man made a testament, would anyone, coming afterward, dare to pervert it or alter it, that is, add anything to it? All the more must this be understood in relation to God.

Commentary on Galatians ↗

Oecumenius

Since from the signs given by them, and from the revealing of the Holy Spirit, and from the cross of Christ, and from those things by which Abraham was saved, faith was shown to save, and not the law; now he seeks to persuade them by a human example. For the phrase "according to men" stands for "according to a human argument and example." And he rightly calls them brothers, having called them foolish. For it is necessary sometimes to rebuke sharply, and sometimes to soften. …

Commentary on Galatians ↗

Jerome

Brothers, I speak in human terms: yet no one rejects or adds to a man's covenant, which has been confirmed. The promises were made to Abraham and to his seed. It does not say, 'and to seeds,' referring to many, but referring to one, 'and to your seed,' who is Christ. Now I say this: the covenant, which was confirmed by God, the law, which came four hundred and thirty years later, does not invalidate the promise, so as to abolish it. For if the inheritance is based on the law, it is no longer based on a promise. …

Commentary on Galatians ↗

Thomas Aquinas

Having proved by authority that the Law does not justify and is not necessary for justification, which is through faith, the Apostle then proves the same point with human reasons. Concerning this he does four things: First, he mentions a human custom; Secondly, he touches on a divine promise (v. 16); Thirdly, he draws his conclusion (v. 17); Fourthly, he shows that the conclusion follows from the premises (v. 18). …

Commentary on Galatians ↗