Luke 1:2

καθὼς implies that the basis of these many written narratives was the παράδοσις of the Apostles, which, by contrast, and by the usual meaning of the word, would be mainly though not necessarily exclusively oral (might include, e.g., the Logia of Mt.). οἱ … τοῦ λόγου describes the Apostles, the ultimate source of information, as men “who had become, or been made, eye-witnesses and ministers of the word”. Both αὐτόπτ. and ὑπηρ. may be connected with τοῦ λόγου, understood to mean the burden of apostolic preaching = the facts of Christ's earthly history. Eye-witnesses of the facts from the beginning (ἀπʼ - ἀρχῆς), therefore competent to state them with authority; servants of the word including the facts (= “all that Jesus began both to do and to teach”), whose very business it was to relate words and facts, and who therefore did it with some measure of fulness. Note that the ἡμῖν after παρέδοσαν implies that Lk. belonged to the second generation (Meyer, Schanz). Hahn infers from the ἡμῖν in Luke 1:1 that Lk. was himself an eye-witness of Christ's public ministry, at least in its later stage.