Matthew 12:40 in the King James Version
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.
Context
39 But he answered them, “An evil and adulterous generation seeks after a sign, but no sign will be given to it but the sign of Jonah the prophet.
40 For as Jonah was three days and three nights in the belly of the huge 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 stand up in the judgment with this generation and will condemn it, for they repented at the preaching of Jonah; and behold, someone greater than Jonah is here.