Galatians 4:13

"But you know that because of weakness." That is, because of bodily weakness, namely, after bonds and blows and imprisonments, which I endured at the hands of those opposed to the preaching.

"I once preached the gospel." What do I say, Paul says, did you not wrong me? Therefore you showed me great honor. For even while being flogged and persecuted (for he says this was a weakness of the flesh), I was proclaiming the gospel to …

(Verse 13) Brothers, I beseech you, you have not harmed me. But you know that because of the weakness of the flesh, I preached the Gospel to you long ago. Connect the following sentence to the previous one, so that it may be made clearer, this is the order we propose: I beseech you, brothers, be like me, because I am also like you. Similar to this is that: We beseech for Christ, be reconciled to God (II Cor. 5:20). And also elsewhere: I beseech, first of all, that supplications, prayers, intercessions, and thanksgivings be made (I Tim. 2:1). Peter's words also say: I ask you, as a fellow elder and a witness of Christ's sufferings (1 Peter 5:1). These words indeed provoke us to humility and shake off the arrogance of bishops, who, as if stationed on some lofty pedestal, barely deign to see mortals and speak to their own subordinates. Let them learn from the Apostle that the wandering and foolish Galatians are called brothers. Let them learn from the gentle words of the reprover saying: I beseech you (1 Corinthians 11). But what he begs is that they may become his imitators, just as he is of Christ; indeed, that he may follow the present place, there is nothing great that he demands: just as he himself became less for them, from greater: so may they ascend from lesser to greater. You have not harmed me, he says. A disciple harms his master if he squanders his teachings and efforts through his negligence. The Galatians had not harmed the Apostle, as they were still keeping his Gospel and commands up to the present time. But certainly, in this way: When I first announced the Gospel to you; and because of the weakness of your flesh, because you were not able to receive the greater sacraments, I preached to you like little children, and I pretended to be weak myself, so that I might gain you who are weak: did you not receive me as an angel, as Christ Jesus? […]

Not to have injured one is indeed no great thing, for no man whatever would choose to hurt wantonly and without object to annoy another who had never injured him. But for you, not only have ye not injured me, but ye have shown me great and inexpressible kindness, and it is impossible that one who has been treated with such attention should speak thus from any malevolent motive. My language then cannot be caused by ill-will; it follows, that it proceeds from affection and solicitude. "Ye did me no wrong; ye know that because of an infirmity of the flesh I preached the Gospel unto you." What can be gentler than this holy soul, what sweeter, or more affectionate! And the words he had already used, arose not from an unreasoning anger, nor from a passionate emotion, but from much solicitude. And why do I say, ye have not injured me? Rather have ye evinced a great and sincere regard for me. For "ye know," he says, "that because of an infirmity of the flesh I preached the Gospel unto you; and that which was a temptation to you in my flesh ye despised not, nor rejected." What does he mean? While I preached to you, I was driven about, I was scourged, I suffered a thousand deaths, yet ye thought no scorn of me; for this is meant by that which was a temptation to you in my flesh ye despised not, nor rejected." Observe his spiritual skill; in the midst of his self-vindication, he again appeals to their feelings by showing what he had suffered for their sakes. This however, says he, did not at all offend you, nor did ye reject me on account of my sufferings and persecutions; or, as he now calls them, his infirmity and temptation. But ye received me as an Angel of God. Was it not then absurd in them to receive him as an Angel of God, when he was persecuted and driven about, and then not to receive him when pressing on them what was fitting?

You know, he says, that in bodily weakness, that is, amid persecutions and dangers, I preached the gospel to you.