Jonah 1:17 (KJV) Now the Lord had prepared a great fish to swallow up Jonah. And Jonah was in the belly of the fish three days and three nights.
Matthew 12:40 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.
Matthew 16:4 A wicked and adulterous generation seeketh after a sign; and there shall no sign be given unto it, but the sign of the prophet Jonas. And he left them, and departed.