Matthew 12:34-40

You brood of vipers, how can you speak good things when you are evil? For the mouth speaks out of that which fills the heart. The good man, from his [inner]good treasure, brings out good things; and the evil man, from his [inner]evil treasure, brings out evil things. But I tell you, on the day of judgment people will have to give an accounting for every careless or useless word they speak. For by your words [reflecting your spiritual condition] you will be justified and acquitted of the guilt of sin; and by your words [rejecting Me] you will be condemned and sentenced.” Then some of the scribes and Pharisees said to Him, “Teacher, we want to see a sign (attesting miracle) from You [proving that You are what You claim to be].” But He replied and said to them, “An evil and adulterous generation [that is morally unfaithful to God] craves and demands a [miraculous] sign; but no sign will be given to it except the sign of the prophet Jonah; [Luke 11:29-32] for just as JONAH WAS THREE DAYS AND THREE NIGHTS IN THE BELLY OF THE SEA MONSTER, so will the Son of Man be three days and three nights in the heart of the earth. [Jon 1:17]