"And in Lystra a certain man without strength in his feet was sitting, a cripple from his mother's womb, who had never walked.
This man heard Paul speaking.
Paul, observing him intently and seeing that he had faith to be healed, said with a loud voice, 'Stand up straight on your feet!'
And he leaped and walked."
Acts 14:8-10
Paul discerned that the man had faith and he acted on that discernment. [Paul perceived that the man had faith. So he knew the man needed to put it in action].
Paul told the man to stand on his feet.
By having him do what he couldn't do before, he gave the man a way to act his faith.