‘And he said to them, “How say they that the Christ is David's son?”
Mark has “How do the scribes say that the Christ is the son of David?” We must assume from this, as mentioned above, that some Rabbis, especially perhaps even with Jesus in mind, were downgrading ‘the Messiah to come' into a lesser David, a mere ‘son of David', in contrast with the glorious figure usually presented. Their idea may well have been someone who was subservient to the Pharisees. There were in fact many differing and varying views about the Messiah as is especially witnessed by the Dead Sea Scrolls where the Messiah of David appears in some cases to be inferior to the Messiah of Aaron. In contrast some of the apocalyptists endowed him with the highest honours.
Jesus was not by His words denying that He was the son of David, for both Matthew and Luke have already made clear in their genealogies that He was. See also Luke 1:27; Luke 1:32; Luke 1:69; Luke 2:11; Luke 18:38-39; Acts 13:34. What He was arguing against was the idea that that was all that He was. As we have seen earlier (on Luke 18:38) ‘Son of David' was not a prominent Messianic title at this time, even though clearly used by some, although as far as Luke is concerned it was certainly used by the blind man whose eyes were opened (Luke 18:38).