When he heard: News of Jesus had reached Jericho, just as it had spread into Gentile regions (3:8).
Jesus, Son of David: Mark does not explain how Bartimaeus knew that Jesus was a descendant of David. He may have believed that Jesus was the Messiah. However, Bartimaeus did not connect this title with political or military hopes, as many people in that time did.
Instead, he understood that Jesus cared for the poor, disabled, lame, and blind. So he asked Jesus for mercy and healing (10:51). This matched how Jesus understood his own mission (compare Luke 4:18–19).