In Matthew 22, after basically frustrating the Pharisees and the Saduccees by answering some really tricky questions, Jesus finally turns the tables on them and asks this question:
41 While the Pharisees were gathered together, Jesus asked them, 42 “What do you think about the Messiah? Whose son is he?” “The son of David,” they replied. 43 He said to them, “How is it then that David, speaking by the Spirit, calls him ‘Lord’? For he says, 44 “‘The Lord said to my Lord: “Sit at my right hand until I put your enemies under your feet.”’[e] 45 If then David calls him ‘Lord,’ how can he be his son?”
The response is silence, and apparent victory:
46 No one could say a word in reply, and from that day on no one dared to ask him any more questions.
What I understand is this - Jesus is pointing out that the Messiah is both David's son and David's Lord. I get that its a good theological point. But why does it silence his critics?