Matthew 12:37

34 O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh.

35 A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things.

36 But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgment.

37 For by thy words thou shalt be justified, and by thy words thou shalt be condemned.

38 Then certain of the scribes and of the Pharisees answered, saying, Master, we would see a sign from thee.

39 But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas:

40 For as Jonas was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth.