Michael Ben Zehabe said this quote
“ Jonah can't see how Assyria could serve any useful purpose. How could this commission better Israel? Jonah might even fear that God will reverse His judgment against Nineveh. If that 'unchanging God' changes His mind about Nineveh's destruction, then Jonah's personal religion won't make sense. (Nu 23:19) The truth is, Jonah is not as overwhelmed by his new assignment as he is by his own small mindedness. (page 5) ”