We are not told exactly when or how the angel appeared to Philip. It possibly happened while he was in Samaria. For Philip, the message from the angel would have required him to make a journey south, a journey that would have taken some days. The fact that an angel appeared to him serves to confirm that the Lord is the one taking the initiative in terms of the spread of the gospel.1
26 Now an angel of the Lord said to Philip, “Rise and go toward the south to the road that goes down from Jerusalem to Gaza.” This is a desert place.