Jesus and Jonah

Jesus was deeply familiar with the Book of Jonah and raised it to one of the more significant books in His Bible, our Old Testament.

The awesome march of the dead - the Men of Nineveh:

"The men of Nineveh will stand up at the judgment with this generation and condemn it, for they repented at the preaching of Jonah; and now something greater than Jonah is here."
Luke 11:32

The mysterious unscientific very hard-to-believe Sign of Jonah which Jesus talks about almost in spitting way but which in fact is the greatest divine Sign humanity has ever received:

"A wicked and adulterous generation looks for a sign, but none will be given it except the sign of Jonah.” Jesus then left them and went away.
Matthew 16:4

But what is the true meaning of the Sign of Resurrection From the Dead On the Third Day?

The marvelous gem of religious literature, Book of Jonah, does contain the answer but not in expressis verbis. Rather, it runs as an underpinning in the contents of the entire book - allahu rahman urahim.

The answer is given explicitly in the New Testament in the Gospel of John chapter 3 verse 16

For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.