Acts 22:15

And it came to pass, that when I was come again to Jerusalem,.... Which was three years after his conversion; for he did not immediately return to Jerusalem, but went into Arabia; and when he returned…

For thou shalt be his witness ... - As an apostle - to testify to all people that the Messiah has come, that he has died, that he has risen, and that he is the Saviour of the world. Of what thou hast…

Thou shalt be his witness unto all - Thou shalt proclaim Christ crucified, both to Jews and Gentiles.

Paul here gives such an account of himself as might serve not only to satisfy the chief captain that he was not that Egyptian he took him to be, but the Jews also that he was not that enemy to their…

For thou shalt be his witness, &c. Thus the commission of the later-called Apostle was in the same terms as those in which Christ had spoken (Act 1:8) to the eleven before his Ascension.

unto all men…