Jamieson, Fausset and Brown on Acts 9:30

30. they brought him down to Cæsarea--on the coast (see on Ac 8:40); accompanying him thus far. But Paul had another reason than his own apprehension for quitting Jerusalem so soon. "While he was praying in the temple, he was in a trance," and received express injunctions to this effect. (See on Ac 22:17-21).

and sent him forth to Tarsus--In Ga 1:21 he himself says of this journey, that he "came into the regions of Syria and Cilicia"; from which it is natural to infer that instead of sailing direct for Tarsus, he landed at Seleucia, travelled thence to Antioch, and penetrated from this northward into Cilicia, ending his journey at Tarsus. As this was his first visit to his native city since his conversion, so it is not certain that he ever was there again. (See on Ac 11:25). It probably was now that he became the instrument of gathering into the fold of Christ those "kinsmen," that "sister," and perhaps her "son," of whom mention is made in Ac 23:16, &c.; Ro 16:7, 11, 21 [Howson].