"But Paul," it says, "departed, having chosen Silas, and being commended to the grace of God." What is this? They prayed it says: they besought God. See on all occasions how the prayer of the brethren can do great things. And now he journeyed by land, wishing even by his journeying to benefit those who saw him. For when indeed they were in haste they sailed, but now not so. "And he went through Syria and Cilicia, confirming the Churches. Then came he to Derbe and Lystra." Mark the wisdom of Paul: he does not go to other cities before he has visited them which had received the Word. For it is folly to run at random. This let us also do: let us teach the first in the first place, that these may not become an hindrance to them that are to come after.
[AD 407] John Chrysostom on Acts 15:39-41