Jonah 1:17

"Now the LORD had prepared a great fish to swallow up Jonah. And Jonah was in the belly of the fish three days and three nights."
Jonah 1:17 (KJV)

Context from Jonah 1

15

So they took up Jonah, and cast him forth into the sea: and the sea ceased from her raging.

16

Then the men feared the LORD exceedingly, and offered a sacrifice unto the LORD, and made vows.

17

Now the LORD had prepared a great fish to swallow up Jonah. And Jonah was in the belly of the fish three days and three nights.