The story of Prophet Yunus (Jonah) being swallowed by a fish is a well-known narrative in Islamic tradition. According to the Quran, Prophet Yunus was sent to the people of Nineveh to guide them toward the worship of Allah. When they initially rejected his message, he became frustrated and left the city without waiting for Allah's command.
As Prophet Yunus set out on a ship, a storm erupted, and the sailors decided to cast lots to determine who was causing the disturbance. The lot fell on Prophet Yunus, and he admitted that he was the cause. At his request, the sailors threw him into the sea, where he was swallowed by a large fish.
Inside the fish's stomach, Prophet Yunus turned to Allah in repentance, glorifying Him and seeking forgiveness. After spending a period in the darkness of the ocean within the belly of the fish, Allah commanded the fish to release Prophet Yunus onto the shore.
This event serves as a lesson about patience, repentance, and the boundless mercy of Allah. It is mentioned in the Quran, primarily in Surah As-Saf'fat (37:139-148).