Jonah was a prophet of God.
God sent him to Nineveh to
warn them that he was going to
destroy them for their sins.
 
When Jonah got to the city, he
cried out and said, "Yet forty days
and Nineveh shall be overthrown!"

So, the people of Nineveh
believed God, proclaimed a fast,
 and put on sackcloth, from the
greatest to the least of them.

Then the word came to the
 king of Nineveh; and he arose
from his throne and laid
aside his robe, covered himself
with sackcloth and sat in ashes.

The people of Nineveh repented.
God spared them.
Yahweh was their redeemer.
There was no Jesus involved.