Jonah (Youns) is a prophet sent by God to warn his people about the impending wrath of God. He decided to quit his job as we say in America. These are some of the verses that talk about Jonah:
37:139 So also was Jonah among those sent (by Us).
وَإِنَّ يُونُسَ لَمِنَ الْمُرْسَلِينَ
37:140 When he ran away (like a slave from captivity) to the ship (fully) laden,
إِذْ أَبَقَ إِلَى الْفُلْكِ الْمَشْحُونِ
37:141 He (agreed to) cast lots, and he was condemned:
فَسَاهَمَ فَكَانَ مِنْ الْمُدْحَضِينَ
37:142 Then the big Fish did swallow him, and he had done acts worthy of blame.
فَالْتَقَمَهُ الْحُوتُ وَهُوَ مُلِيمٌ
37:143 Had it not been that he (repented and) glorified Allah,
فَلَوْلَا أَنَّهُ كَانَ مِنْ الْمُسَبِّحِينَ
37:144 He would certainly have remained inside the Fish till the Day of Resurrection. لَلَبِثَ فِي بَطْنِهِ إِلَى يَوْمِ يُبْعَثُونَ
37:145 But We cast him forth on the naked shore in a state of sickness,
فَنَبَذْنَاهُ بِالْعَرَاء وَهُوَ سَقِيمٌ
37:146 And We caused to grow, over him, a spreading plant of the gourd kind.
وَأَنبَتْنَا عَلَيْهِ شَجَرَةً مِّن يَقْطِينٍ
37:147 And We sent him (on a mission) to a hundred thousand (men) or more.
وَأَرْسَلْنَاهُ إِلَى مِئَةِ أَلْفٍ أَوْ يَزِيدُونَ
37:148 And they believed; so We permitted them to enjoy (their life) for a while.
فَآمَنُوا فَمَتَّعْنَاهُمْ إِلَى حِينٍ
Verses from www.islamicity.com Translation to Yusuf Ali.