Cambridge Greek Testament Commentary
Luke 1 - Introduction
Title. Εὐαγγέλιον. See Introd. ch. 1. The word has come to mean not the ‘good news’ in the abstract but the ‘written Gospel,’ a sense which it acquired before the end of the first century. But if the title of this Gospel came from the original writer it was used in its earlier and proper sense.
κατὰ Λουκᾶν. The preposition κατὰ implies the authorship of St Luke, just as ἡ καθ' Ἡρόδοτον ἱστορία in Diodorus means the history written by Herodotus, and ἡ κατὰ Μωϋσέα πεντάτευχος in Epiphanius means the Pentateuch written by Moses (Godet). Possibly however the expression originated from the currency of oral forms of teaching systematically adopted by different Apostles, which, when reduced to writing, were not represented as exclusive presentations of the Good Tidings, but as the Gospel in the particular form wherein it was preached by St Peter, St Matthew, or by other Apostles.
κατὰ Λουκᾶν. In אBF we have simply this title, but most MSS. add εὐαγγέλιον. Others have τὸ or ἐκ τοῦ, and some add ἅγιον before εὐαγγέλιον, or have ἐκ τοῦ κατὰ Λ. ἁγίου εὐαγγελίου. The earliest titles are the simplest.