I feared he would reach his house before I did, so I stamped my foot on the ground. He turned to me, and I turned back toward him.
He said, “Abu Ishaq?”
I replied, “Yes, O Messenger of Allah!”
He asked, “So what is it?”
I said, “By Allah, nothing except that you mentioned to us the first supplication, and then that Bedouin came.”
He said, “Yes. It is the supplication of Dhu ’l-Nun: ‘There is no deity but You; glory be to You! I was indeed among the wrongdoers’ (al-Anbiyaʾ 21:87). No Muslim ever calls upon his Lord with it regarding anything whatsoever without His answering him (1).”

Al-Tirmidhi recorded it through the chain of al-Firyabi from Yunus.

Ibn Wahb said: Usama ibn Zayd al-Laythi narrated to me; Ibn Shihab narrated to me:
that ʿAbd al-Rahman ibn al-Miswar said: I set out with my father, with Saʿd, and with ʿAbd al-Rahman ibn al-Aswad ibn ʿAbd Yaghuth in the year of Adhruh. When the plague struck Syria, we stayed at Sargh for fifty nights, and Ramadan came upon us. Al-Miswar and ʿAbd al-Rahman fasted, whereas Saʿd broke his fast and refused to fast.
I said to him, “Abu Ishaq! You are a Companion of the Messenger of Allah ﷺ, you fought at Badr, yet you are eating while they are fasting?”
He replied, “I have a deeper understanding than they do (2).”

Ibn Jurayj said: Zakariyya ibn ʿAmr (3) narrated to me that Saʿd ibn Abi Waqqas had come to