Jesus recently healed a blind man, and now the blind man's neighbors saw that something changed with the blind man (who was also a beggar).
The changes prompted people to have discussions. Some thought the healed man was the blind man, while others didn't think so. But in the midst of the discussions, the formerly blind man revealed that he was the one who used to be blind (9:9). The peeps also asked how the formerly blind man was able to see, and that's when the formerly blind man told others that some Jesus guy told him to wash in the pool of Siloam (9:11). Though the formerly blind man did not know where Jesus was when others asked for his location.
Often times, after Jesus does some crazy work (especially in transformation), some people can take notice. These scenarios are often ripe for others to see who Jesus is and what impact He can do. Jesus's work can start conversations!