The official could not understand what he was reading.

Acts 8:29-31

29 God’s Spirit told Philip, “Go near to that chariot and keep walking close to the man who is riding in it!” 30 So Philip ran to the chariot and kept running close to it. Then he heard the official reading what the prophet Isaiah had written. He asked the man, “Do you (sg) understand what you are reading?” 31 He answered Philip, “No! ◄I cannot possibly understand it if there is no one to explain it to me!/How can I understand it if there is no one to explain it to me?► [RHQ]”