Acts 16:16

And it came to pass, as we were going to the place of prayer, that a certain maid having a spirit of divination met us, who brought her masters much gain by soothsaying. The same following after Paul and us cried out, saying, These men are servants of the Most High God, who proclaim unto you the way of salvation. And this she did for many days. But Paul, being sore troubled, turned and said to the spirit, I charge thee in the name of Jesus Christ to come out of her. And it came out that very hour.

As we were going to the place of prayer ... Evidently, Paul and company made daily visits to the place of prayer. This caught the attention of the demoniac girl; and, for some time, she made a habit of following them and crying out an endorsement of their message.

Spirit of divination ... The Greek here has "A Python spirit," thus Luke identified this unfortunate girl as one coming from the pagan temple at Delphi, where the Pythian Apollo was worshiped, the python being sacred to him, and his devotees being said to have the python spirit. Luke's identification of this girl with that pagan establishment contains no suggestion whatever of any validity in their outlandish claims. Rather, Paul's addressing the "spirit" in her clearly indicates exactly the same kind of demon possession so often healed by our Lord.

Servants of the Most High God ... The Gerasene demoniacs used this same expression regarding Jesus (Mark 5:7), this speech of the girl thus proving the fact of her being possessed by a demon.

Paul being sore troubled ... Paul's problem was simple, but difficult as well. The slave-masters who were exploiting this alleged soothsayer were making a lot of money out of her. They knew she was a fraud, else they would have believed it when she identified Luke and Paul and company as servants of the Most High God showing the right way of salvation. Paul therefore knew that if he cast the demon out of her, there would be a sharp conflict with the evil men who owned her. He delayed acting as long as he properly could, hoping perhaps that she would desist; but when she continued, Paul cast the demon out. He, even as the Lord, could not afford an endorsement of one so clearly evil; and furthermore, any sign or miracle that Paul might have performed would have been seized upon by the masters of the girl in an effort to exploit such to their own benefit.