Seventeen verses in the New Testament describe Jesus as the “son of David.” But the question arises, how could Jesus be the son of David if David lived approximately 1000 years before Jesus? The answer is that Christ (the Messiah) was the fulfillment of the prophecy of the seed of David (2 Samuel 7:14-16). Jesus was the promised Messiah, which meant He was of the seed of David. Matthew 1 gives the genealogical proof that Jesus, in His humanity, was a direct descendant of Abraham and David through Joseph, Jesus’ legal father. The genealogy in Luke chapter 3 gives Jesus’ lineage through His mother, Mary. Jesus is a descendant of David, by adoption through Joseph, and by blood through Mary.
Jesus was addressed as “Lord, thou son of David” several times by people who, by faith, were seeking mercy or healing. The woman whose daughter was being tormented by a demon (Matthew 15:22), the two blind men by the wayside (Matthew 20:30), and blind Bartimaeus (Mark 10:47), all cried out to the son of David for help. The titles of honor they gave Him declared their faith in Him. Calling Him Lord expressed their sense of His deity, dominion, and power, and by calling Him “son of David,” they were professing Him to be the Messiah.
The Pharisees, too, understood what was meant when they heard the people calling Jesus “son of David.” But unlike those who cried out in faith, they were so blinded by their own pride and lack of understanding of the Scriptures that they couldn’t see what the blind beggars could see – that here was the Messiah they had supposedly been waiting for all their lives. They hated Jesus because He wouldn’t give them the honor they thought they deserved, so when they heard the people hailing Jesus as the Savior, they became enraged (Matthew 21:15) and plotted to destroy Him (Luke 19:47).
Jesus further confounded the scribes and Pharisees by asking them to explain the meaning of this very title. How could it be that the Messiah is the son of David when David himself refers to Him as “my Lord” (Mark 12:35-37)?.He was neither denying His credentials to be the Messiah nor the fact that the Messiah would be a “Son of David.” On the contrary, Jesus was trying to get His hearers to understand that the Messiah, though David’s Son, is greater than David, for King David called Him “my Lord.” It was self-evident to first-century Jews that the Messiah would be a descendant of David (Psalm 89:3-4; 132:11-12; Isaiah 9:6-7; Matthew 1:1-16; 12:23; 21:9,15; Luke 3:23-38). Jesus was not denying that fact. Rather, He wanted his hearers to reach the same conclusion that Peter previously reached after Jesus asked a similar question: “Who do people say that the Son of Man is?” (Matthew 16:13, NASB). Peter confessed to Jesus: “You are the Christ, the Son of the living God” (Matthew 16:16). How could the Messiah be a descendant of David as well as be the One to whom David 1,000 years earlier called “Lord”? Answer: He was deity Who put on flesh. This is the truth with which Jesus confronted the Pharisees, and “no one was able to answer Him a word” (Matthew 22:46)
Jesus thereby exposed the Jewish spiritual leaders’ ineptitude as teachers and their ignorance of what the Old Testament taught as to the true nature of the Messiah, further alienating them from Him.
So in conclusion,primarily though, when Christ was referred to as the Son of David, it was meant to refer to His Messianic title as the Old Testament prophesied concerning Him.