The interpretation timeline
3 John 1:9 Douay-Rheims

I had written perhaps to the church: but Diotrephes, who loveth to have the pre-eminence among them, doth not receive us.

1714 – 1871 5 witnesses

Post-Reformation

c. 1650 – 1900
1714
A.D.
Matthew Henry Reformed
1662–1714
“I. Diotrephes, unlike Gaius, loved preeminence and refused apostolic authority, spreading malicious words. He did not accept John’s letter and discouraged others from showing hospitality, casting them out of the church. John warns that he will address this behavior when he visits. II. John cautions against following Diotrephes’ evil example and encourages believers to imitate what is good, for those who do good are of God, while those who do evil have not seen God.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“I wrote unto the Church - The Church where Caius was; but Diotrephes, who loveth to have the pre-eminence, φιλοπρωτευων, who loves the presidency, or chief place in the Church. He was doubtless an officer in the Church, at least a deacon, probably a bishop; and, being one, he magnified himself in his office; he loved such eminence, and behaved himself haughtily in it. Receiveth us not - Does not acknowledge the apostolical authority. As some MSS. supply αν after εγραψα, and several judicious critics believe it is implied, the translation will run thus: I would have written to the Church to receive these men kindly, but Diotrephes, who affects the presidency; and into whose hands, if I wrote to the Church, my letter must come, receiveth us not - would not acknowledge my authority to interfere with any of the matters of his Church; and therefore I have written unto thee, whose love to the brethren and general hospitality are well known, that thou wouldst receive those strangers and persecuted followers of our common Lord.”
Source
1849
A.D.
1774–1849
“Diotrephes….doth not receive us, nor those we recommend, but prattles and talks against me. We know no more of this man, nor of Demetrius, of whom St. John gives so favourable a character. (Witham) — It seemeth, saith Ven. Bede, that he was an arch heretic, or proud sect master— upomneso . I will rebuke them, and make them known to be wicked. (Ven. Bede)”
Source
1871
A.D.
1871
“I wrote--The oldest manuscripts add "something": a communication, probably, on the subject of receiving the brethren with brotherly love (Jo3 1:8, Jo3 1:10). That Epistle was not designed by the Spirit for the universal Church, or else it would have been preserved. unto the church--of which Gaius is a member. loveth . . . pre-eminence--through ambition. Evidently occupying a high place in the Church where Gaius was (Jo3 1:10). among them--over the members of the Church. receiveth us not--virtually, namely, by not receiving with love the brethren whom we recommended to be received (Jo3 1:8, Jo3 1:10; compare Mat 10:40).”
Source

Undated

date unknown
date
unknown
Glossa Ordinaria Medieval
“I would perhaps have written, etc. You ought to persevere in almsgiving, for I understand so great a usefulness in it that I would have written of the commendation of almsgiving not only to you but even to the whole Church; but I let this go of necessity, because Diotrephes does not regard our authority. Diotrephes, a heresiarch of that time, was usurping headship for himself by teaching novelties. Diotrephes is interpreted speciously foolish, or beauty running mad, so that he might mark the treachery of his heart even by his name. To the Church. I would have written to that Church which is perhaps — that is, doubtfully — a Church, and that through the practice of almsgiving it might deserve to become a perfect Church.”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.