The Lord give mercy unto the house of Onesiphorus; for he oft refreshed me, and was not ashamed of my chain:
Paul asserts his apostolic authority not for Timothy's sake alone; Timothy already believed. He writes with these grand titles because he stands at death's door and means to seal his whole ministry with his blood, that the Church may know his doctrine comes from God Himself, not from a mortal man's opinion.
AI summary
Commenting on 2 Timothy 1:1-18
Having (Ti2 1:13, Ti2 1:14) exhorted Timothy to hold fast, I. He mentions the apostasy of many from the doctrine of Christ, Ti2 1:15. It seems, in the best and purest ages of the church, there were those that had embraced the Christian faith, and yet afterwards revolted from it, nay, there were many such.
Commenting on 2 Timothy 1:15-18
The Lord give mercy to the house of Onesiphorus,.... Who seems to have been one of Asia, and of Ephesus, and is an exception from the general apostasy, or from those that turned away from the apostle; and therefore he prays that the Lord would show mercy to his family; that he would give regenerating grace and mercy to such of them as were without...