Jonah was a fantastically (flawed, scared, unbelieving, complaining) human prophet (who did exist) that foreshadows Jesus in unmistakable ways. On the boat, Jonah was sacrificed to appease YHWH for Jonah's disobedience and stop the storm, yet Jesus was perfectly obedient, both willing and able to do it the Father's way. Then the men were exceedingly afraid and said to him, “What is this that you have done!” For the men knew that he was fleeing from the presence of the Lord (YHWH), because he had told them. So they picked up Jonah and hurled him into the sea, and the sea ceased from its raging. Then the men feared the Lord (YHWH) exceedingly, and they offered a sacrifice to the Lord (YHWH) and made vows. Jonah 1:10‭, ‬15‭-‬16 ESV Jonah and Jesus could not be seen for 3 days, were sustained in order to fulfill the Father's will, yet Jesus overcame not just a fish's belly, but the depths of Sheol/Hades in death. Then he said to them, “These are my words that I spoke to you while I was still with you, that everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled.” Then he opened their minds to understand the Scriptures, and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance for the forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. You are witnesses of these things. And behold, I am sending the promise of my Father upon you...” Luke 24:44‭-‬49a ESV Ultimately, Jonah's message to repentance for Ninevah was heard and received, saving many, all the while he continued to grumble and complain because it wasn't the process or outcome he ever wanted for himself... Yet Jesus returned with a new body (forever able to save all who accept, believe and follow him), then left again in order that the Holy Spirit might come so that his followers could be made righteous and blameless to prepare for him to ultimately come again when YHWH has decided. When God saw what they did, how they turned from their evil way, God relented of the disaster that he had said he would do to them, and he did not do it. Jonah 3:10 ESV And the Pharisees and Sadducees came, and to test him they asked him to show them a sign from heaven. He answered them, “When it is evening, you say, ‘It will be fair weather, for the sky is red.’ And in the morning, ‘It will be stormy today, for the sky is red and threatening.’ You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times. An evil and adulterous generation seeks for a sign, but no sign will be given to it except the sign of Jonah.” So he left them and departed. Matthew 16:1‭-‬4 ESV