Adam Clarke on Acts 8:35

Began at the same scripture - He did not confine himself to this one scripture, but made this his text, and showed, from the general tenor of the sacred writings, that Jesus was the Christ, or Messiah; and that in his person, birth, life, doctrine, miracles, passion, death, and resurrection, the Scriptures of the Old Testament were fulfilled. This preaching had the desired effect, for the eunuch was convinced of the truth of Philip's doctrine, and desired to be baptized in the name of Jesus.