Jer 23:5, Mt 22:41-42, Rev 22:16
The Old Testament prophesied that Christ would come as the son of David. (Jer 23:5)
Jer 23:5 Behold, the days come, saith the Lord, that I will raise unto David a righteous Branch, and a King shall reign and prosper, and shall execute judgment and justice in the earth.
After the fall of the nation of Israel, there was no more king, no priests, and no more prophets. So, the waiting for Christ that God would send happened to all the people. All the people were expecting that Christ to come and do the work of a true king, a true priest, and a true prophet.
At this time, a blind man felt Jesus passing by and called to Jesus, Son of David. The descendants of David are nicknames for Christ. That is, he called Jesus as the Christ. (Mk 10:46-47)
Mk 10:46 And they came to Jericho: and as he went out of Jericho with his disciples and a great number of people, blind Bartimaeus, the son of Timaeus, sat by the highway side begging. 47 And when he heard that it was Jesus of Nazareth, he began to cry out, and say, Jesus, thou son of David, have mercy on me.
The Jews knew that Christ would come in the blood of David. (Mt 22:41-42)
Mt 22:41 While the Pharisees were gathered together, Jesus asked them, 42 Saying, What think ye of Christ? whose son is he? They say unto him, The son of David.
Jesus is the Christ who fulfilled the work of the true king, true priest, and true prophet who came as the descendant of David. (Rev 22:16)
Rev 22:16 I Jesus have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star.