Charles Ellicott Commentary 2 Timothy 1:18

"(the Lord grant unto him to find mercy of the Lord in that day); and in how many things he ministered at Ephesus, thou knowest very well." — 2 Timothy 1:18 (ASV)

The Lord grant to him that he may find mercy of the Lord in that day...—The Greek should be rendered here, favour of the Lord, instead of by "mercy of the Lord." Some commentators, who have found a difficulty in this unusual repetition of "the Lord," explain it this way: The expression, "the Lord grant," had become so completely "a formulary" among Christians that the second use of the word "Lord" was not noticed, and the prayer is thus simply equivalent to "Oh, that he may find mercy of the Lord." It seems, however, better to keep to the strict, literal meaning and to understand the first "Lord" in the sense in which the term is always found in the Epistles of St. Paul, as a title of Christ, and the second "Lord" as used of the Father, to whom here (Romans 2:16; Hebrews 12:23), judgment at the last day is ascribed.

In that day.—The Apostle can never repay now—not even with thanks—the kindness his dead friend showed him in his hour of need; so he prays that the Judge of quick and dead may remember it in the awful day of judgment. It is worthy of note how St. Paul’s thoughts here pass over the interval between death and judgment. It was on that day when the great white throne would be set up that he thought of the good deeds done in the body being recompensed by the righteous Judge. No doubt the expectation of the early Christians—in which expectation St. Paul certainly shared—of the speedy coming of the Lord influenced all thinking and speaking about the intermediate state of the soul between death and judgment, and almost seems to have effaced the waiting time from their minds.

And in how many things he ministered to me at Ephesus, you know very well.—These services rendered to St. Paul at Ephesus are placed side by side with those things he had done for him at Rome, but as they are mentioned after, they perhaps refer to kind services undertaken for the prisoner by Onesiphorus after his return from Rome to Ephesus. These things Timothy, the presiding pastor at Ephesus, would, of course, know in their detail better than St. Paul. The Greek word διηκόνσεν, rendered "he ministered," has given rise to the suggestion that Onesiphorus was a deacon at Ephesus. Although this is possible, still such an inference from one rather general expression is precarious.

This passage is famous because it is generally quoted among the very rare statements in the New Testament which seem to relate to the question of the Roman Catholic doctrine of praying for the dead.

It may be useful to touch very briefly on two points which suggest themselves regarding the bearing of this passage on the doctrine in question.

1. Although we here, in common with Roman Catholic interpreters and the majority of later expositors of the Reformed Church, assume that Onesiphorus was dead when St. Paul wrote to Timothy, and that the words used referred to St. Paul’s dead friend, it must still be remembered that others, well worthy of being heard, writing many centuries before any doctrinal controversy on this subject arose, held quite a different opinion. Theodoret and Chrysostom (quoted by Alford) understood that Onesiphorus was with St. Paul at this time.
2. The prayer, whether it is taken as a prayer or a brief, fervent prayer, is simply the expression of an earnest desire on St. Paul's part that the kind act of the dead—assuming, contrary to the opinion of the above-quoted Fathers, that he was dead—Onesiphorus towards himself may be remembered on that day when the books are opened before the Judge of quick and dead. Indeed, it only asks—looking fairly at the context—that an act of unrequited and devoted love shown in this life may be remembered in the final judgment. Without touching upon the controversy itself, it seems only just to point out the extreme precariousness of pressing this text—the only one in the New Testament really touching on this subject, and about whose interpretation expositors, as we have seen, are by no means in agreement—in support of a controverted doctrine.