Jamieson, Fausset and Brown on Acts 8:5

Ac 8:5-25. Success of Philip's Preaching in Samaria--Case of Simon Magus.

5. Then Philip--not the apostle of that name, as was by some of the Fathers supposed; for besides that the apostles remained at Jerusalem, they would in that case have had no occasion to send a deputation of their own number to lay their hands on the baptized disciples [Grotius]. It was the deacon of that name, who comes next after Stephen in the catalogue of the seven, probably as being the next most prominent. The persecution may have been directed especially against Stephen's colleagues [Meyer].

the city of Samaria--or "a city of Samaria"; but the former seems more likely. "It furnished the bridge between Jerusalem and the world" [Baumgarten].