The answer is: Jonah

Matt 12:38-39 - Referring to the three days and nights that Jonah has spent in the belly of the great fish

When the Scribes and Pharisees demanded a sign from Jesus, his reference to Jonah hit like a prophetic mic drop. This wasn’t just an off-the-cuff reply; it deliberately echoed a dramatic part of Jonah’s story from the Old Testament. Jonah spent three days and nights in the belly of a gigantic fish— a journey that resembles a kind of ‘death and resurrection’ before he does the unthinkable: goes back to deliver a message to the very people he tried to escape from.

Now, what's fascinating about this is that Jonah, often seen as the reluctant prophet, is your classic underdog. His tale is so rich it moves beyond just a guy and a fish into realms of repentance, divine mercy, and the importance of compliance with one’s calling— themes underpinning the message of Jesus too.

Don't forget— “three days and nights” becomes a major echo in the Gospels. Just like Jonah, Jesus responds to the Scribes and Pharisees about his impending death and resurrection after three days, emphasizing a new revelation of authority.

It's interesting that to modern ears, Jonah’s story reads more like an epic adventure than a prophet’s diary. The irony here is that while Jesus points to Jonah for a sign, those experts in the law seemed oblivious to the profound symbolism of the prediction right in front of them. It's as if they were looking for fireworks, unaware they were already engaging in a kingdom drama unfolding right before their eyes!