Prophet Yunus (AS) / Jonah (PBUH) was sent to preach the people of Nineveh. However people rejected him and didn't accept his call. Yunus (AS) left his people telling them that the punishment of Allah (SWT) will come upon them in 3 days. Yunus (AS) left his people although Allah had not yet commanded him to do so, when the Prophet boarded the ship; soon the sky drew dark and there was a terrible storm. Yunus (AS) understood it was because he left without the permission of Allah (SWT). People drew lots and whoever name appears must jump from the ship so that the ship doesn't drown because of overweight. Yunus (AS) name came and he jumped from the ship and Allah commanded a big fish to swallow him. In the belly of the fish, Yunus (AS) sincerely repented to Allah and his Tawbah was accepted. Allah ordered the fish to vomit Yunus (AS) on the shore. Yunus (AS) went back to his people and saw that all accepted his message when he left because of the warning he gave them about the punishment of Allah. Dua of Yunus (AS) لَّا إِلَٰهَ إِلَّا أَنتَ سُبْحَانَكَ إِنِّي كُنتُ مِنَ الظَّالِمِين "There is no god (worthy of worship) except You. Glory be to You! I have certainly done wrong.” [Surah Anbiya 87-88]