2 Thess 3:17

3:17 Though Paul had the help of secretaries in writing his letters, he customarily penned the final greeting or benediction in his own hand. He calls attention to this practice, as a mark of the letter’s authenticity, here and in 1 Cor. 16:21; Col. 4:18. From Gal. 6:11 and Philem. 19, it appears that Paul wrote more than just the concluding phrases of those two letters.