Acts 16:18

τοῦτο δέ ἐποίει ἐπὶ πολλάς ἡμέρας, this she did for many days. Whether this following took place only on the sabbaths, when the Apostles were going to the place of prayer, in which case the Apostles must have remained in Philippi some weeks, or whether it was on every occasion on which they appeared in public, we are not told.

διαπονηθεὶς δὲ Παῦλος, but Paul being grieved. The same verb is used (Acts 4:2) of the annoyance of the priests and Sadducees at the teaching of the Apostles, and nowhere else in N.T. (See note there.) Its sense is ‘to be thoroughly worn out with vexation.’

τῷ πνεύατι εἶπεν, said to the spirit. As Christ had acted when on earth, so Paul now will not allow the cry of the evil spirit, even though the words proclaim that he and his companions are servants of the Most High God. So in Christ’s name he bids the evil power come forth.