When Jesus and his disciples had gone to the town of Jericho, a blind beggar called out to Jesus. Jesus miraculously cured him of his blindness. As explained in the Gospel of Mark:
46 They came to Jericho. As he went out from Jericho with his disciples and a great multitude, the son of Timaeus, Bartimaeus, a blind beggar, was sitting by the road. 47 When he heard that it was Jesus the Nazarene, he began to cry out and say, “Jesus, you son of David, have mercy on me!” 48 Many rebuked him, that he should be quiet, but he cried out much more, “You son of David, have mercy on me!”
49 Jesus stood still and said, “Call him.”
They called the blind man, saying to him, “Cheer up! Get up. He is calling you!”
50 He, casting away his cloak, sprang up, and came to Jesus.
51 Jesus asked him, “What do you want me to do for you?”
The blind man said to him, “Rabboni, that I may see again.”
52 Jesus said to him, “Go your way. Your faith has made you well.” Immediately he received his sight and followed Jesus on the way. (Mark 10:46-52, WEB)
The phrase "Son of David" was a way to refer to the Messiah who had been promised by the prophets of the Old Testament. The Messiah was to be a descendant of King David who had lived about a thousand years before Jesus. The Gospels of Matthew and Luke say that Jesus was a descendant of King David, in addition to proclaiming that he is the promised Messiah.
Matthew mentions that there was a second blind man who also was healed with Bartimaeus.
Read more in the book Jesus the Miracle Worker: The 50 miracles of Jesus explained in chronological order (The Jesus Series) -- now available at amazon.
Next: 45. Healing the blind and lame at the Temple (Matthew 21:12-17)