Scribes and Pharisees demand a sign

Mat 12:38-45

38 Then some of the scribes and Pharisees, hearing this, said to him, Master, we are looking for a sign from you.
39 But he, answering, said to them, An evil and false generation is looking for a sign; and no sign will be given to it but the sign of the prophet Jonah:
40 For as Jonah was three days and three nights in the stomach of the great fish, so will the Son of man be three days and three nights in the heart of the earth.
41 The men of Nineveh will come up in the day of judging and give their decision against this generation: because they were turned from their sins at the preaching of Jonah; and now a greater than Jonah is here.
42 The queen of the South will come up in the day of judging and give her decision against this generation: for she came from the ends of the earth to give ear to the wisdom of Solomon; and now a greater than Solomon is here.
43 But the unclean spirit, when he is gone out of a man, goes through dry places looking for rest, and getting it not.
44 Then he says, I will go back into my house from which I came out; and when he comes, he sees that there is no one in it, but that it has been made fair and clean.
45 Then he goes and takes with him seven other spirits worse than himself, and they go in and make it their living-place: and the last condition of that man is worse than the first. Even so will it be with this evil generation.