But you shall receive power, after the Holy Spirit has come upon you: and you shall be witnesses unto me both in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of the earth.
All Commentaries on Acts 1:8 Go To Acts 1
Thomas Aquinas
AD 1274
you shall be witnesses for me: He adds why this testimony is appropriate when he says in John's Gospel (15:27), because you have been with me from the beginning, that is, the beginning of my preaching and working of miracles, and so you can testify to what you have seen and heard.