A.T. Robertson Commentary Acts 2:22

"Ye men of Israel, hear these words: Jesus of Nazareth, a man approved of God unto you by mighty works and wonders and signs which God did by him in the midst of you, even as ye yourselves know;" — Acts 2:22 (ASV)

Hear these words (ακουσατε τους λογους τουτους). Do it now (aorist tense). With unerring aim Peter has found the solution for the phenomena. He has found the key to God's work on this day in his words through Joel.

as ye yourselves know (καθως αυτο οιδατε). Note αυτο for emphasis. Peter calls the audience to witness that his statements are true concerning "Jesus the Nazarene." He wrought his miracles by the power of God in the midst of these very people here present.