Kings shall Shut their Mouths at Him

Isaiah 52:15 So shall He sprinkle many nations. Kings shall shut their mouths at Him; For what had not been told them they shall see, And what they had not heard they shall consider.

This was read at our carol service. One particular phrase stood out: 'Kings shall shut their mouths at him'. It intrigued me: what does it mean?

When kings speak, others listen. Whether it be a judgement, a law or a command, kings give orders. Courtiers and ministers enact their will. Others desist from speaking when kings open their mouths. But Isaiah sees a time when the world's most powerful people will shut up. One is coming, says the prophet, whose words will be so great and powerful that the great will be silenced.
One is coming whose status will outrank kings. Only one modern monarchy claims imperial status- Japan, with its emperor. He technically outranks all other heads of state.  Yet he is outranked by the One Isaiah foresaw. For Christ is the King of kings and the Lord of lords.
One is coming whose story will be of far greater interest than kings'. Glossy magazines love to follow the royal family's comings and goings. I know that the Queen is currently suffering from a cold. Although glamorous monarchs are of interest, the majesty and lineage of Christ is from eternity; His mission involving death and resurrection would be the talk of angels. Kings shut their mouths at Him for His story is far greater than theirs. 
Isaiah saw Him coming; we have seen Him come. Happy Christmas.