Acts 1:8
But you shall receive power, after that the Holy Ghost is come on you: and you shall be witnesses to me both in Jerusalem, and in all Judaea, and in Samaria, and to the uttermost part of the earth.
Nave's Topical Index—AKJV

Acts 5:32
And we are his witnesses of these things; and so is also the Holy Ghost, whom God has given to them that obey him.
Nave's Topical Index—AKJV

Acts 26:16
But rise, and stand on your feet: for I have appeared to you for this purpose, to make you a minister and a witness both of these things which you have seen, and of those things in the which I will appear to you;
Nave's Topical Index—AKJV