In the Iviron monastery on Mt Athos, there is a Georgian manuscript (shelfmark: Athos Iviron 11) which contains a work with the title, “The Word of Saint Barsabas, Archbishop of Jerusalem, about our Savior Jesus Christ and the Churches [and about the High Priests].” The text itself is a homily, in which various Old Testament figures and events are shown to be “types”, prefigurings, of Christ and the church. The Georgian text is itself a translation of a lost Greek original. The work is assigned the reference number CPG 1685.
The text was first published, together with a French translation, by Michel van Esbroeck in the Patrologia Orientalis 41 (1982), pp.151-256. A draft text and English translation has been made by David P. George, which is accessible on Academia.edu here.
There seems to be only a limited amount of scholarship about this work. Esbroeck considered that the theology of the work meant that it should be dated early, to the second or third century AD. He dismissed the identification of the author as an Archbishop of Jerusalem, still less Barsabas Justus, the third bishop of Jerusalem, but agreed that it was probably written at that location. Quite sensibly van Esbroeck refuses to call the author “pseudo Barsabas”, when we know so little about any Barsabas at all.
There is a useful discussion of the work and its contents by Dmitry F. Bumazhnov, “The Jews in the Neglected Christian Writing “The Word of Saint Barsabas, Archbishop of Jerusalem, about our Saviour Jesus Christ and the Churches” of the Second – Early Third Century”, in: Scrinium 4 (2008), 121–135. Online here. A search on Bumazhnov indeed brings up a number of other papers discussing Barsabas.
On his Twitter account recently, Dr. George included a quote suggesting that, at such a date, this could be the earliest mention of the Trinity:
Now this is very interesting, but obvious raises issues. The word “Trinity” is a fingerprint, and we all know that that word originates with Tertullian, around 217 AD. I don’t feel competent to enter into the various issues about the supposed date of the work. But I would be very wary of interpolation or gloss here. Generally when a word or phrase is the badge of a controversy, we need to date any text using it later than the beginning of that controversy. When a work clearly written earlier uses it, we may well suppose that a later copyist has added a clarifying note. I would suspect that this is what has happened here.

Thank you for featuring Barsabas!
Since Theophilus of Antioch does use the term “Trinity / Triad” (τριάς), I think it would not be implausible that the homily, if dated to roughly the same period, used the same or a similar term. Though this could indeed be a later gloss, given the largely unknown textual transmission of the work (which is still interesting).
I wonder what the Greek word was in Barsabbas. But yes, that phrase tacked on the end smelt a bit of gloss to me
Thank you so very much for making that translation! It will open up the world. What sort of state is the text in?
Thank you for that.
The text as preserved in the Georgian manuscript is incomplete: there is at least one (long) gap, right before the forty-second section. Hopefully, other manuscript witnesses will be discovered in the future (perhaps in Armenian, since early Armenian sources do appear to have been aware of Barsabas’ homily, in some form). I also do wish that scholars will pay due attention to the text, and prepare an academic translation based directly on the Georgian.
Thank you. That’s well worth knowing!
I always found it hard to work with catalogues of Armenian manuscripts because they tended to be written in Armenian. If this is general, it may explain why there is so much to discover. Another copy of Barsabas would be wonderful!