This story is mentioned here, and in Surat As-Saffat and Surah Nun. Yunus bin Matta, upon him be peace, was sent by Allah to the people of Nineveh, which was a town in the area of Mawsil in northern Iraq. He called them to Allah, but they rejected him and persisted in their disbelief. So he left them in anger, threatening them with punishment after three days. When they realized that he was telling the truth and that a Prophet never lies, they went out to the desert with their children and cattle and flocks. They separated the mothers from their children, then they beseeched Allah and pleaded to Him, with the camels and their young groaning, the cows and their calves mooing, and the sheep and their lambs bleating, so Allah spared them from the punishment. Allah says:

فَلَوْلاَ كَانَتْ قَرْيَةٌ ءَامَنَتْ فَنَفَعَهَآ إِيمَانُهَا إِلاَّ قَوْمَ يُونُسَ لَمَّآ ءَامَنُواْ كَشَفْنَا عَنْهُمْ عَذَابَ الخِزْىِ فِى الْحَيَوةَ الدُّنْيَا وَمَتَّعْنَاهُمْ إِلَى حِينٍ

(Was there any town that believed (after seeing the punishment), and its faith saved it Except the people of Yunus; when they believed, We removed from them the torment of disgrace in the life of the world, and permitted them to enjoy for a while) 10:98. Yunus, meanwhile, went and traveled with some people on a ship, which was tossed about on the sea. The people were afraid that they would drown, so they cast lots to choose a man whom they would throw overboard. The lot fell to Yunus, but they refused to throw him overboard. This happened a second and a third time. Allah says:

فَسَـهَمَ فَكَانَ مِنَ الْمُدْحَضِينَ

(Then he (agreed to) cast lots, and he was among the losers.) 37:141 meaning, the draw went against him, so Yunus stood up, removed his garment and cast himself into the sea. Then Allah sent from the Green Sea -- according to what Ibn Mas`ud said -- a large fish which cleaved the oceans until it came and swallowed Yunus when he threw himself into the sea. Allah inspired that large fish not to devour his flesh or break his bones, (as if He said) Yunus is not food for you, rather your belly is a prison for him.

وَذَا النُّونِ

(And (remember) Dhun-Nun,) Here Nun refers to the fish; it is correct for it to be attributed to him here.

إِذ ذَّهَبَ مُغَـضِباً

(when he went off in anger,) Ad-Dahhak said: "Anger towards his people."

فَظَنَّ أَن لَّن نَّقْدِرَ عَلَيْهِ

(and imagined that We shall not punish him!) meaning, constrict him in the belly of the fish. Something similar to this was reported from Ibn `Abbas, Mujahid, Ad-Dahhak and others. This was the view favored by Ibn Jarir, and he quoted as evidence for that the Ayah:

وَمَن قُدِرَ عَلَيْهِ رِزْقُهُ فَلْيُنفِقْ مِمَّآ ءَاتَاهُ اللَّهُ لاَ يُكَلِّفُ اللَّهُ نَفْساً إِلاَّ مَآ ءَاتَاهَا سَيَجْعَلُ اللَّهُ بَعْدَ عُسْرٍ يُسْراً

(and the man whose resources are restricted, let him spend according to what Allah has given him. Allah puts no burden on any person beyond what He has given him. Allah will grant after hardship, ease) 65:7.

فَنَادَى فِى الظُّلُمَـتِ أَن لاَّ إِلَـهَ إِلاَّ أَنتَ سُبْحَـنَكَ إِنِّى كُنتُ مِنَ الظَّـلِمِينَ

(But he cried through the depths of darkness (saying): "There is no God but You, Glorified be You! Truly, I have been of the wrongdoers.") Ibn Mas`ud said regarding the `depths of darkness': "The darkness of the belly of the fish, the darkness of the sea and the darkness of the night." This was also narrated from Ibn `Abbas, `Amr bin Maymun, Sa`id bin Jubayr, Muhammad bin Ka`b, Ad-Dahhak, Al-Hasan and Qatadah. Salim bin Abu Al-Ja`d said: "The darkness of the fish in the belly of another fish in the darkness of the sea." Ibn Mas`ud, Ibn `Abbas and others said: "This was because the fish took him through the sea, cleaving it until it reached the bottom of the sea. Yunus heard the rocks at the bottom of the sea uttering glorification of Allah, at which point he said:

لاَّ إِلَـهَ إِلاَّ أَنتَ سُبْحَـنَكَ إِنِّى كُنتُ مِنَ الظَّـلِمِينَ

(There is no God but You, Glorified be You! Truly, I have been of the wrongdoers)" `Awf Al-A`rabi said: "When Yunus found himself in the belly of the fish, he thought that he had died. Then he moved his legs. When he moved his legs, he prostrated where he was, then he called out: `O Lord, I have taken a place of worship to You in a place which no other person has reached."'

فَاسْتَجَبْنَا لَهُ وَنَجَّيْنَـهُ مِنَ الْغَمِّ

(So `We answered his call, and delivered him from the distress.) means, `We brought him forth from the belly of the fish and from that darkness.'

وَكَذلِكَ نُنجِـى الْمُؤْمِنِينَ

(And thus We do deliver the believers.) means, when they are in difficulty and they call upon Us and repent to Us, especially if they call upon Us with these words at the time of distress. The leader of the Prophets encouraged us to call upon Allah with these words. Imam Ahmad recorded that Sa`d bin Abi Waqqas, may Allah be pleased with him, said: "I passed by `Uthman bin `Affan, may Allah be pleased with him, in the Masjid, and greeted him. He stared at me but did not return my Salam. I went to `Umar bin Al-Khattab and said: `O Commander of the faithful, has something happened in Islam' I said that twice. He said, `No, why do you ask' I said, `I passed by `Uthman a short while ago in the Masjid and greeted him, and he stared at me but he did not return my Salam.' `Umar sent for `Uthman and asked him, `Why did you not return your brother's Salam' He said, `That is not true.' Sa`d said, `Yes it is.' It reached the point where they both swore oaths. Then `Uthman remembered and said, `Yes, you are right, I seek the forgiveness of Allah and I repent to Him. You passed by me a short while ago but I was preoccupied with thoughts of something I had heard from the Messenger of Allah ﷺ, which I never think of but a veil comes down over my eyes and my heart.' Sa`d said: `And I will tell you what it was. The Messenger of Allah ﷺ told us the first part of the supplication then a bedouin came and kept him busy, then the Messenger of Allah ﷺ got up and I followed him. When I felt worried that he would enter his house, I stamped my feet. I turned to the Messenger of Allah ﷺ, who said,

«مَنْ هَذَا، أَبُو إِسْحَاقَ؟»

(Who is this Abu Ishaq) I said, "Yes, O Messenger of Allah." He said,

«فَمَه»

(What is the matter) I said, "Nothing, by Allah, except that you told us the first part of the supplication, then this bedouin came and kept you busy." He said,

«نَعَمْ دَعْوَةُ ذِي النُّونِ إِذْ هُوَ فِي بَطْنِ الْحُوتِ

(Yes, the supplicaiton of Dhun-Nun when he was in the belly of the fish:

لاَّ إِلَـهَ إِلاَّ أَنتَ سُبْحَـنَكَ إِنِّى كُنتُ مِنَ الظَّـلِمِينَ

(There is no God but You, Glorified be You! Truly, I have been of the wrongdoers.)

فَإِنَّهُ لَمْ يَدْعُ بِهَا مُسْلِمٌ رَبَّهُ فِي شَيْءٍ قَطُّ إِلَّا اسْتَجَابَ لَه»

No Muslim ever prays to his Lord with these words for anything, but He will answer his prayer.)" It was also recorded by At-Tirmidhi, and by An-Nasa'i in Al-Yawm wal-Laylah. Ibn Abi Hatim recorded that Sa`d said that the Messenger of Allah ﷺ said:

«مَنْ دَعَا بِدُعَاءِ يُونُسَ اسْتُجِيبَ لَه»

(Whoever offers supplication in the words of the supplication of Yunus, will be answered.) Abu Sa`id said: "He was referring to:

وَكَذلِكَ نُنجِـى الْمُؤْمِنِينَ

(And thus We do deliver the believers.)"