People there were astonished that Saul had believed in Jesus.

Acts 9:20-22

20 Right away Saul began to preach to people about Jesus in the Jewish meeting places in Damascus. He told them that Jesus is ◄the Son of/the man who is also► God. 21 And all the people who heard him preach were amazed. Various ones of them were saying, “◄We(inc) can hardly believe that this is the same man who persecuted the believers in Jerusalem!/Is this really the same man who persecuted the believers in Jerusalem?► [RHQ, MTY] And we (inc) know that he has [RHQ] come here to seize us and take us to the chief priests in Jerusalem!” 22 But God enabled Saul to preach to many people even more convincingly. He was proving from the Scriptures that Jesus is the Messiah. So the Jewish leaders in Damascus could not think of anything ◄to refute what he said/to prove that what he said was not true►.