The Author of Hebrews

Ὁ χαρακτὴρ τῆς λέξεως τῆς πρὸς Ἑβραίους ἐπιγεγραμμένης Ἐπιστολῆς οὐκ ἔχει τὸ λόγῳ ἰδιωτικὸν τοῦ Ἀποστόλου, ὁμολογήσαντος ἑαυτὸν ἰδιώτην εἴναι τῷ λόγῳ, τουτέστι, τῇ φράσει. Ἀλλὰ ἐστὶν ἡ Ἐπιστολὴ συνθέσει τῆς λέξεως ἑλληνικωτέρα, πᾶς ὁ ἐπιστάμενος κρίνειν φράσεων διαφορὰς, ὁμολογήσαι ἄν· πάλιν τε αὖ ὅτι τὰ νοήματα τῆς ἐπιστολῆς θαυμάσιά ἐστι, καὶ οὐ δεύτερα τῶν ἀποστολικῶν ὁμολογουμένων γραμμάτων, καὶ τοῦτο ἄν συμφήσαι εἶναι ἀληθὲς πᾶς ὁ προσέχων τῇ ἀναγνώσει τῇ ἀποστολικῇ. Ἐγὼ δὲ ἀποφαινόμενος εἴποι μ' ἄν, ὅτι τὰ μὲν νοήματα τοῦ Ἀποστόλου ἐστὶν, ἡ δὲ φράσις, καὶ ἡ σύνθεσις, ἀπομνημονεύσαντός τινος τὰ ἀποστολικὰ, καὶ ὡσπεριεὶ σχολιογραφήσαντος τὰ εἰρημένα ὑπὸ τοὺ διδασκάλου. Εἰ τις οὖν Ἐκκλησία ἔχει ταύτην τὴν Ἐπιστολὴν ὡς Παύλου, αὔτη εὐδοκιμείτω καὶ ἐπὶ τούτῳ, οὐ γὰρ εἰκῆ οἱ ἀρχαῖοι ἄνδρες ὡς Παύλου αὐτὴν παραδεδώκασι. Τίς δὲ ὁ γράψας τὴν Ἐπιστολὴν, τὸ μὲν ἀληθὲς Θεὸς οἴδεν.  Ὠριγένης, Ὁμιλίαι Πρὸς Ἑβραίους Ἐπιστολὴς

The character of the writing style of the letter entitled to the Hebrews does not have the roughness of speech which the Apostle himself confesses to, that is, in the phrasing. Rather the letter is fashioned more in the Greek way, as anyone able to distinguish differences of style would admit; but even so the thought of the letter is wonderful, and not inferior to the acknowledged writings of the Apostle, and anyone who has read the Apostle carefully would agree to the truth of this. If I were asked to declare myself, I would say that the thought is the Apostle's but the phrasing and the arrangement are by someone who remembered the Apostolic teaching and, just like a recorder of a lesson, wrote his own version of the things spoken by his teacher. If, then, any church holds this letter to be Paul's, let it be commended for it, for not without reason did the men before us hand it down as Paul's. But who wrote the letter is known to God alone. Origen, Homily on the Epistle to the Hebrews 1 2 Cor 11.6