Jamieson, Fausset and Brown on 1 Thessalonians 5:27

27. I charge--Greek, "I adjure you."

read unto all--namely, publicly in the congregation at a particular time. The Greek aorist tense implies a single act done at a particular time. The earnestness of his adjuration implies how solemnly important he felt this divinely inspired message to be. Also, as this was the FIRST of the Epistles of the New Testament, he makes this the occasion of a solemn charge, that so its being publicly read should be a sample of what should be done in the case of the others, just as the Pentateuch and the Prophets were publicly read under the Old Testament, and are still read in the synagogue. Compare the same injunction as to the public reading of the Apocalypse, the LAST of the New Testament canon (Re 1:3). The "all" includes women and children, and especially those who could not read it themselves (De 31:12; Jos 8:33-35). What Paul commands with an adjuration, Rome forbids under a curse [Bengel]. Though these Epistles had difficulties, the laity were all to hear them read (1Pe 4:11; 2Pe 3:10; even the very young, 2Ti 1:5; 3:15). "Holy" is omitted before "brethren" in most of the oldest manuscripts, though some of them support it.