I thank my God always. We ought, therefore, to thank God, not only for gifts bestowed upon ourselves, but also for those bestowed upon others. This is an habitual phrase of St. Paul (comp. Romans 1:8; i Corinthians Romans 1:4; Ephesians 1:16; Philippians 1:3; 1 Thessalonians 1:2; 2 Thessalonians 1:3; 2 Timothy 1:3).
"It is to be noted that for the thing on account of which he gives thanks, he at the same time prays" (Calvin). For no good work is ever so complete in us that it does not need to be "continued and ended" in us by God.
Making mention of thee in my prayers. The foregoing remark attain applies. Grotius observes that "we learn from this that all addresses to God may be called prayers προσευχὰς, even those in which nothing is asked but thanks are given."
But this is apparently not such a case; the petition which St. Paul offered for Philemon being stated in Philemon 1:6. And thus Chrysostom explains the passage. "Always" may be connected with "I thank," or with "making mention," preferably the former (Chrysostom, Theophylact, Calvin, Lightfoot).