Matthew 12:37

34 You offspring of snakes, how are you, being evil, able to say good things? because out of the heart's store come the words of the mouth.

35 The good man out of his good store gives good things; and the evil man out of his evil store gives evil things.

36 And I say to you that in the day when they are judged, men will have to give an account of every foolish word they have said.

37 For by your words will your righteousness be seen, and by your words you will be judged.

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.