Jamieson, Fausset and Brown on 1 Timothy 1:17

17. A suitable conclusion to the beautifully simple enunciation of the Gospel, of which his own history is a living sample or pattern. It is from the experimental sense of grace that the doxology flows [Bengel].

the King, eternal--literally, "King of the (eternal) ages." The Septuagint translates Ex 15:18, "The Lord shall reign for ages and beyond them." Psa 145:13, Margin, "Thy kingdom is an everlasting kingdom," literally, "a kingdom of all ages." The "life everlasting" (1Ti 1:16) suggested here "the King eternal," or everlasting. It answers also to "for ever and ever" at the close, literally, "to the ages of the ages" (the countless succession of ages made up of ages).

immortal--The oldest manuscripts read, "incorruptible." The Vulgate, however, and one very old manuscript read as English Version (Ro 1:23).

invisible--(1Ti 6:16; Ex 33:20; Joh 1:18; Col 1:15; He 11:27).

the only wise God--The oldest manuscripts omit "wise," which probably crept in from Ro 16:27, where it is more appropriate to the context than here (compare Jude 25). "The only Potentate" (1Ti 6:15; Psa 86:10; Joh 5:44).

for ever, &c.--See note, above. The thought of eternity (terrible as it is to unbelievers) is delightful to those assured of grace (1Ti 1:16) [Bengel].