John Chrysostom

He does not immediately at the commencement ask the favor, but having first admired the man, and having praised him for his good actions, and having shown no small proof of his love, that he always made mention of him in his prayers, and having said that many are refreshed by him, and that he is obedient and complying in all things; then he puts it last of all, by this particularly putting him to the blush. For if others obtain the things which they ask, much more Paul. …

Homily on Philemon 2 ↗

Theophylact of Ohrid

Every time, he says, I remember you – and I remember you always when I pray – so many times I thank God for your virtue. What this virtue is, he explains further.

Commentary on Philemon ↗

Oecumenius

If ever "I" make "mention of you", I always do, "I give thanks to God" for you. Why? "Hearing of your love and faith", he says. Do you see that he does not immediately seek favor from the beginning? "hearing of your love". which, if it were not great, would by no means be heard from Phrygia all the way to Rome.

Commentary On Philemon ↗

Jerome

This, now not as Paul and Timothy, to Philemon and others; but as Paul alone, speaks only to Philemon: "I give thanks," he says, "always to my God, making mention of thee in my prayers." It is said ambiguously, whether he always gives thanks to his God, or whether he always mentions him in his prayers. And both can be understood. For whoever commands others to give thanks to God in all things, cannot be restricted by any difficulties to himself not to give thanks to God always.

Commentary on Philemon ↗

Thomas Aquinas

Then when he says, I give thanks to my God, the burden of the letter begins. First, he gives thanks; then he makes his plea, For this reason...; finally, he concludes, For I had great joy... Again, first he expresses thanks; second he gives the reason for his gratitude: as I hear of your charity...; third, the reason why he thanks God: For I had great joy and consolation... I give thanks to my God. …

Commentary on Philemon ↗