Jesus is saying clearly that he is a greater prophet than those who went before, but no one is listening to him.
The signs of divine favour, of power, that people demand are not part of his ministry.
That was a principle laid down during the time that we call "the Temptations".
(and a principle that charismatic teachers today might note.)
A sign, a miracle, will not change the situation.
Where there were signs, healings and miracles, reported in the Gospels,
Jesus is often said to have asked for silence about them.
They are not the focus of his ministry.
The text in Matthew's Gospel confuses things by adding that bit about the heart of the earth for three days,
and then adds an attack on those who are converted to Jesus but then turn back to their old ways.
Matthew is following his own agenda and twists the legends of Jesus to make his own point,
as do the other Gospel writers, in their own way.
Jesus is concerned that people are not listening to him.
People came for many miles to listen to Solomon, but they are discarding his teaching.
When Jesus does anything special, they say that he is in collusion with the Devil.
It is a distraction from his message, clouds what he is preaching.
Their eyes are closed and their minds confused.
The "Sign of Jonah" was of forgiveness in the face of provocation,
of patience in the face of ongoing wickedness,
of acceptance of real repentance,
of divine forgiveness.
The Kingdom of God works like yeast through the dough of humanity.
We demand signs of God's immediate presence through evidence of divine power
but the teaching of Jesus, of Jonah, even of Solomon, was of patience and obedience.
Our route to holiness is slow and indirect, wandering through wars and divisions,
as humanity turns slowly from the struggles of individualism to mutual love.
We may not be convinced by any sign, but we can travel that extra mile
Maybe we may hear the wisdom of a second Solomon
one to help us hear God's call more clearly.