John Gill Commentary Philemon 1:4

"I thank my God always, making mention of thee in my prayers," — Philemon 1:4 (ASV)

I thank my God Meaning on account of Philemon, for the grace bestowed upon him, thereafter mentioned; (See Gill on Romans 1:8) making other saints, (Romans 1:9) (Ephesians 1:16) (Philippians 1:3Philippians 1:4) (Colossians 1:3) (1 Thessalonians 1:2) ,

the apostle was a man much in prayer, frequent at the throne of grace; and he prayed not for himself only, but for all the saints, for all the churches and ministers of the Gospel; whom he not only bore upon his mind and heart, but made mention of them, it may be by name; however, he remembered them, and put up petitions, with thanksgivings, for them; and so he did for Philemon; and which he takes notice of with the same view as before:

the word, "always", is so placed in the original text, as to be put either to his thanks to God, or his prayers, and may be true of both; the Syriac and Arabic versions join it to the former; and the Vulgate Latin and the Ethiopic versions place it to the latter.