Du’aa made by Prophet Yunus (Alyhissalam) in the belly of the whale.
(Surah Al Anbiyaa 87-88)
The Prophet (SallAllahu Alyhi wasallam) said to his companions:
“Shall I not tell you some words which, if distress or grief befalls any of you and he makes this du’aa, it will bring him joy? It is the du‘aa’ of Dhoo’l-Noon (i.e. Yunus or Jonah): ‘There is no god but You, Glory to You; verily I was one of the wrongdoers.’”
(Saheeh al-Jaami‘, no. 2605).
It was narrated that Sa’d ibn Abi Waqqaas (may Allaah be pleased with him) said: The Prophet (SallAllahu Alyhi wasallam) said: “The prayer of Dhu’l-Noon when he was in the belly of the fish: ‘Laa ilaaha illa Anta, subhaanaka inni kuntu min al-zaalimeen (There is no god but You, glory to You, verily I was one of the wrongdoers).’ A Muslim never calls upon his Lord with these words concerning any matter, but his prayer is answered.”
(Narrated by al-Tirmidhi, 3505; classed as saheeh by al-Albaani in al-Silsilah al-Saheehah, 1644)