As I began to speak (en tōi arxasthai me lalein). En with the locative of the articular aorist infinitive arxasthai (punctiliar action simply) and the accusative of general reference. The second infinitive lalein (to speak) is dependent on arxasthai, “In the beginning to speak as to me.”
Even as on us at the beginning (hōsper kai eph' hēmās en archēi). Peter recalls vividly the events at Pentecost, the speaking with tongues and all. It is noteworthy that Peter does not here repeat his sermon. “He rests his defence, not on what he said, but on what God did” (Furneaux).