Jewish expectation commonly associated the Messiah with David's royal line. Jesus accepts the Davidic framework but asks a question that forces his opponents to reckon with a Messiah greater than David.
Sitting at the right hand of a ruler signifies supreme delegated honor and authority. Psalm 110 became one of the New Testament's most important texts for understanding Jesus' exaltation.
Psalm 110:1 distinguishes the LORD from the figure David calls 'my Lord': the LORD invites David's Lord to sit at his right hand until his enemies are subdued.
Because the figures are distinguished, this should not be described as a simple equation of the Messiah with YHWH. The Christological force lies in the Messiah's extraordinary heavenly status beside God.
Jesus asks the Pharisees whose son the Christ is. When they answer 'David's,' he asks how David, speaking in the Spirit, can call the Messiah 'Lord.'
The unanswered question does not deny Jesus' Davidic descent. It demonstrates that 'son of David' is insufficient to encompass the Messiah's true identity and exaltation.
The passage is strong evidence of transcendent messianic identity but should be stated precisely. Psalm 110 contains distinction as well as exaltation.
Matthew will soon combine this right-hand imagery with Daniel 7 at Jesus' trial, where the Son of Man is portrayed as enthroned beside God and coming with the clouds of heaven.
No one is able to answer Jesus, and from that day no one dares to question him further.