Luke indicated that Jesus said that just as Jonah became a sign to the people of Nineveh (καθὼς γὰρ ἐγένετο Ἰωνᾶς τοῖς Νινευείταις σημεῖον), so, too, the Son of Man will be a sign to this generation (οὕτως ἔσται καὶ ὁ Υἱὸς τοῦ ἀνθρώπου τῇ γενεᾷ ταύτῃ). This saying about the sign of Jonah can also be found in Matthew, chapter 12:39-40. Perhaps this was a Q source, going back to Hebrew scripture roots. Jesus used this story of the prophet Jonah, chapter 1:17, where he was in the belly of the whale or the sea monster for 3 days and 3 nights. The obvious comparison between the 3 days and 3 nights in the belly of the fish and Jesus in the tomb was not lost on the early Christians. Matthew was even more specific than Luke. He indicated that Jesus said that the only sign they were going to get was the sign of the prophet Jonah, who had been in the belly of the sea monster or whale that swallowed him for 3 days and 3 nights. Thus, the Son of Man would be 3 days and 3 nights in the heart of the earth. This was a clear allusion to the death of Jesus in the tomb for 3 days and 3 nights before his resurrection. Luke was not as clear or specific. What do you know about Jonah and the whale?
Here we get to the great story of Jonah and the whale that has delighted young children for centuries. First, is this the end of the 1st chapter or the beginning of the 2nd chapter? Is this a male of female fish? There are many interpretations about this fish. Was it a big fish or a whale? Was it a special fish just for this one occasion that Yahweh provided it? Is this just an allegorical story like a dream or vision? Most people have interpreted this large fish as a whale or shark. However, most whales could not swallow a whole human. Perhaps, it was a sea monster or a sea serpent. The obvious comparison between the 3 days and 3 nights in the belly of the fish and Jesus in the tomb was not lost on the early Christians.