John Gill Commentary Acts 14:9

"The same heard Paul speaking, who, fastening eyes upon him, and seeing that he had faith to be made whole," — Acts 14:9 (ASV)

The same heard Paul speak
That is, preach the Gospel; he was one of his hearers, and faith came to him by hearing; the Arabic version adds, "he cried unto him"; that is, to Paul, whom he heard:

who steadfastly beholding him ;
not the lame man beholding Paul, but Paul beholding the lame man, as the Syriac and Ethiopic versions both express it, as also Beza's ancient copy and others; so Peter looked on the man he cured, (Acts 3:4) .

And perceiving that he had faith to be healed ;
as he might by his looks, his gestures, his attention in hearing, and it may be by somewhat that he said, as well as by revelation, or a spirit of discerning, which he had.