Syriac was once known as a Hebrew tounge. According to Eusebius of Caesarea, the Hebrews used a Syriac Gospel (εὐαγγελίου καὶ τοῦ Συριακοῦ). This is taken from Eusebius’ Ecclesiastical History, Book IV, Chapter 22.
ἔκ τε τοῦ καθ᾿ Ἑβραίους εὐαγγελίου καὶ τοῦ Συριακοῦ καὶ ἰδίως ἐκ τῆς Ἑβραΐδος διαλέκτου τινὰ τίθησιν, ἐμφαίνων ἐξ Ἑβραίων ἑαυτὸν πεπιστευκέναι, καὶ ἄλλα δὲ ὡς ἐξ Ἰουδαϊκῆς ἀγράφου παραδόσεως μνημονεύει
And from the Syriac Gospel according to the Hebrews he quotes some passages in the Hebrew tongue, showing that he was a convert from the Hebrews, and he mentions other matters as taken from the unwritten tradition of the Jews.
Hebrew tounge (Ἑβραΐδος διαλέκτου) above is best translated as Hebrew dialect, in this case, the Hebrew dialect is Syriac.
The full text of Ecclesiastical History, Book IV, Chapter 22:-
1. Hegesippus in the five books of Memoirs which have come down to us has left a most complete record of his own views. In them he states that on a journey to Rome he met a great many bishops, and that he received the same doctrine from all. It is fitting to hear what he says after making some remarks about the epistle of Clement to the Corinthians.
Ὁ μὲν οὖν Ἡγήσιππος ἐν πέντε τοῖς εἰς ἡμᾶς ἐλθοῦσιν ὑπομνήμασιν τῆς ἰδίας γνώμης πληρεστάτην μνήμην καταλέλοιπεν· ἐν οἷς δηλοῖ ὡς πλείστοις ἐπισκόποις συμμίξειεν ἀποδημίαν στειλάμενος μέχρι Ῥώμης, καὶ ὡς ὅτι τὴν αὐτὴν παρὰ πάντων παρείληφεν διδασκαλίαν. ἀκοῦσαί γέ τοι πάρεστιν μετά τινα περὶ τῆς Κλήμεντος πρὸς Κορινθίους ἐπιστολῆς
2. His words are as follows: And the church of Corinth continued in the true faith until Primus was bishop in Corinth. I conversed with them on my way to Rome, and abode with the Corinthians many days, during which we were mutually refreshed in the true doctrine.
αὐτῷ εἰρημένα ἐπιλέγοντος ταῦτα· καὶ ἐπέμενεν ἡ ἐκκλησία ἡ Κορινθίων ἐν τῷ ὀρθῷ λόγῳ μέχρι Πρίμου ἐπισκοπεύοντος ἐν Κορίνθῳ· οἷς συνέμιξα πλέων εἰς Ῥώμην καὶ συνδιέτριψα τοῖς Κορινθίοις ἡμέρας ἱκανάς, ἐν αἷς συνανεπάημεν τῷ ὀρθῷ λόγῳ·
3. And when I had come to Rome I remained there until Anicetus, whose deacon was Eleutherus. And Anicetus was succeeded by Soter, and he by Eleutherus. In every succession, and in every city that is held which is preached by the law and the prophets and the Lord.
γενόμενος δὲ ἐν Ῥώμῃ, διαδοχὴν ἐποιησάμην μέχρις Ἀνικήτου· οὗ διάκονος ἦν Ἐλεύθερος, καὶ παρὰ Ἀνικήτου διαδέχεται Σωτήρ, μεθ᾿ ὃν Ἐλεύθερος. ἐν ἑκάστῃ δὲ διαδοχῇ καὶ ἐν ἑκάστῃ πόλει οὕτως έχει ὡς ὁ νόμος κηρύσσει καὶ οἱ προφῆται καὶ ὁ κύριος.
4. The same author also describes the beginnings of the heresies which arose in his time, in the following words: And after James the Just had suffered martyrdom, as the Lord had also on the same account, Symeon, the son of the Lord’s uncle, Clopas, was appointed the next bishop. All proposed him as second bishop because he was a cousin of the Lord.
Therefore, they called the Church a virgin, for it was not yet corrupted by vain discourses.
ὁ δ᾿ αὐτὸς καὶ τῶν κατ᾿ αὐτὸν αἱρέσεων τὰς ἀρχὰς ὑποτίθεται διὰ τούτων·
καὶ μετὰ τὸ μαρτυρῆσαι Ἰάκωβον τὸν δίκαιον, ὡς καὶ ὁ κύριος, ἐπὶ τῷ αὐτῷ λόγῳ, πάλιν ὁ ἐκ θείου αὐτοῦ Συμεὼν ὁ τοῦ Κλωπᾶ καθίσταται ἐπίσκοπος, ὃν προέθεντο πάντες, ὄντα ἀνεψιὸν τοῦ κυρίου δεύτερον.διὰ τοῦτο ἐκάλουν τὴν ἐκκλησίαν παρθένον, οὔπω γὰρ ἔφθαρτο ἀκοαῖς ματαίαις·
5. But Thebuthis, because he was not made bishop, began to corrupt it. He also was sprung from the seven sects among the people, like Simon, from whom came the Simonians, and Cleobius, from whom came the Cleobians, and Dositheus, from whom came the Dositheans, and Gorthæus, from whom came the Goratheni, and Masbotheus, from whom came the Masbothæans. From them sprang the Menandrianists, and Marcionists, and Carpocratians, and Valentinians, and Basilidians, and Saturnilians. Each introduced privately and separately his own peculiar opinion. From them came false Christs, false prophets, false apostles, who divided the unity of the Church by corrupt doctrines uttered against God and against his Christ.
ἄρχεται δὲ ὁ Θεβουθὶς διὰ τὸ μὴ γενέσθαι αὐτὸν ἐπίσκοπον ὑποφθείρειν ἀπὸ τῶν ἑπτὰ αἱρέσεων, ὧν καὶ αὐτὸς ἦν, ἐν τῷ λαῷ, ἀφ᾿ ὧν Σίμων, ὅθεν Σιμωνιανοί, καὶ Κλεόβιος, ὅθεν Κλεοβιηνοί, καὶ Δοσίθεος, ὅθεν Δοσιθιανοί, καὶ Γορθαῖος, ὅθεν Γοραθηνοί, καὶ Μασβώθεοι. ἀπὸ τούτων Μενανδριανισταὶ καὶ Μαρκιανισταὶ καὶ Καρποκρατιανοὶ καὶ Οὐαλεντινιανοὶ καὶ Βασιλειδιανοὶ καὶ Σατορνιλιανοὶ ἕκαστος ἰδίως καὶ ἑτεροίως ἰδίαν δόξαν παρεισηγάγοσαν, ἀπὸ τούτων ψευδόχριστοι, ψευδοπροφῆται, ψευδαπόστολοι, οἵτινες ἐμέρισαν τὴν ἕνωσιν τῆς ἐκκλησίας φθοριμαίοις λόγοις κατὰ τοῦ θεοῦ καὶ κατὰ τοῦ Χριστοῦ αὐτοῦ.
6. The same writer also records the ancient heresies which arose among the Jews, in the following words:
There were, moreover, various opinions in the circumcision, among the children of Israel. The following were those that were opposed to the tribe of Judah and the Christ: Essenes, Galileans, Hemerobaptists, Masbothæans, Samaritans, Sadducees, Pharisees.ἔτι δ᾿ ὁ αὐτὸς καὶ τὰς πάλαι γεγενημένας παρὰ Ἰουδαίοις αἱρέσεις ἱστορεῖ λέγων· ἦσαν δὲ γνῶμαι διάφοροι ἐν τῇ περιτομῇ ἐν υἱοῖς Ἰσραηλιτῶν κατὰ τῆς φυλῆς Ἰούδα καὶ τοῦ Χριστοῦ αὗται· Ἐσσαῖοι Γαλιλαῖοι Ἡμεροβαπτισταὶ Μασβώθεοι Σαμαρεῖται Σαδδουκαῖοι Φαρισαῖοι.
7. And he wrote of many other matters, which we have in part already mentioned, introducing the accounts in their appropriate places. And from the Syriac Gospel according to the Hebrews he quotes some passages in the Hebrew tongue, showing that he was a convert from the Hebrews, and he mentions other matters as taken from the unwritten tradition of the Jews.
καὶ ἕτερα δὲ πλεῖστα γράφει, ὧν ἐκ μέρους ἤδη πρότερον ἐμνημονεύσαμεν, οἰκείως τοῖς καιροῖς τὰς ἱστορίας παραθέμενοι, ἔκ τε τοῦ καθ᾿ Ἑβραίους εὐαγγελίου καὶ τοῦ Συριακοῦ καὶ ἰδίως ἐκ τῆς Ἑβραΐδος διαλέκτου τινὰ τίθησιν, ἐμφαίνων ἐξ Ἑβραίων ἑαυτὸν πεπιστευκέναι, καὶ ἄλλα δὲ ὡς ἐξ Ἰουδαϊκῆς ἀγράφου παραδόσεως μνημονεύει.
8. And not only he, but also Irenæus and the whole company of the ancients, called the Proverbs of Solomon All-virtuous Wisdom. And when speaking of the books called Apocrypha, he records that some of them were composed in his day by certain heretics. But let us now pass on to another.
οὐ μόνος δὲ οὗτος, καὶ Εἰρηναῖος δὲ καὶ ὁ πᾶς τῶν ἀρχαίων χορὸς πανάρετον Σοφίαν τὰς Σολομῶνος Παροιμίας ἐκάλουν. καὶ περὶ τῶν λεγομένων δὲ ἀποκρύφων διαλαμβάνων, ἐπὶ τῶν αὐτοῦ χρόνων πρός τινων αἱρετικῶν ἀναπεπλάσθαι τινὰ τούτων ἱστορεῖ. ἀλλὰ γὰρ ἐφ᾿ ἕτερον ἤδη μεταβατέον,