Sous cet Adrien se réunit à Nicée un premier synode de 43 évoques qui anathématisèrent [Sa]bellius, qui blasphémait en disant que le Père, le Fils et le Saint-Esprit ne sont qu'une seule personne manifestée en trois [manières] ; ils anathématisèrent aussi Valentinus qui disait que Notre-Seigneur avait fait descendre son corps du ciel.
Which as the translator notes is from the same source as this statement in Bar Hebraeus:
And the Christian philosophers KURTOS (QUADRATUS?) and ARISTIDES, the ATHENIANS, wrote an Apologia for the doctrine of the Christians. And SAYRAINOS (SERENUS) the governor wrote to the Emperor [saying], 'It is not right to kill them merely because of the name Ch;istian, without any blameworthy act'; and the Emperor wrote, 'Unless there is a reason for condemnation they shall not die'. And in his days the First Council in NICEA was gathered together, namely forty-three bishops; and they excommunicated SABELLIUS, who said, 'One Person of the Trinity', and VALENTlNUS, who confessed that our Lord brought a body for Himself from heaven. [Bar Hebraeus Chr. syr 51, 52]
This fits our basic reconstruction of the earliest period of Christianity quite perfectly. What's more, Celsus also seems to mention Christian Σιβυλλισται (sibyl-mongers or believers in sibyls). We have already noted the parallels between Celsus and the original Latin syntagma.
The French translator of Michael the Syrian manages to trace the tradition back one step further noting "Pseudo-Denis (edit. Tullberg, p. 154) : « à Ancyre»; ce doit être la vraie lecture. Cependant il y a un anachronisme, ce concile ayant été célébré vers 314. Voir les canons édités en syriaque, dans Pitr*, Analecta sacra, IV, 443, Il n'y est pas question de Sabellius qui fut condamné au concile de Nicée. BH (Chr. syr., P 53). [= Pseudo-Denis (edit. Tullberg, p. 154) "at Ancyra" this must be the true reading. However, there is an anachronism, this council has been celebrated in 314. See canons published in Syriac in Pitr * Analecta sacra, IV, 443 There is no question of Sabellius was condemned at the Council of Nicaea.] 'Pseudo-Denis' = Dionysius of Tel-Mahre author of the late eighth-century universal chronicle in Syriac. Brent Landau has noted that this chronicle (Chronicle of Zuqnin—Codex Vaticanus Syriacus 162) "incorporates a number of pre-existing writings of various genres in its compilation of the history of the world from creation up to its time of composition, 775-776 CE."
