This question finishes the one Jesus began in Mark 12:35. If David, the great king, calls the Christ "Lord," then the Christ cannot be merely David's descendant. The word "whence" asks where His sonship comes from, how He can be both. Mark records no answer, and the question is left for His hearers to wrestle with. Gill says the point is that the Messiah "was God, as well as man." Matthew Henry says the scribes found their ignorance exposed, while the common people heard Him with gladness.

No one answers. Mark records only the reaction: "And the common people heard him gladly" (Mark 12:37). Jesus then turns to warn them, "Beware of the scribes" (Mark 12:38). Matthew adds that "no man was able to answer him a word, neither durst any man from that day forth ask him any more questions" (Matthew 22:46). The answer the text points to is that the Christ is both David's son and David's Lord.

"The common people" were the ordinary crowds in the temple. Gill describes them as "the populace in general," everyone except the scribes and Pharisees, who listened "with great pleasure and satisfaction." Barnes notes that Jesus' preaching had its success "chiefly among the common or the poorer class," since "the rich and the mighty were too proud to listen."

Jesus' question points to a mystery the rest of the New Testament makes plain. Paul says Jesus was "made of the seed of David according to the flesh" and "declared to be the Son of God with power" by the resurrection (Romans 1:3-4). The question in the temple prepares for that answer.

The response also shows how God works. The experts had no answer, but ordinary people listened with joy. Barnes says this is "not the fault of the gospel": it would bless the rich and the mighty as well as the poor if they came with like humble hearts. What opens a person to Jesus is not status but humility.