Acts 22:15

15Forὅτιyou will beἔσῃa witnessμάρτυςfor Himαὐτῷtoπρὸςallπάνταςmenἀνθρώπουςof whatὧνyou have seenἑώρακαςandκαὶheardἤκουσας.

For you will be a witness for Him to all men of what you have seen and heard.