Surah Nūn
In the name of Allah, the Most Merciful, the Bestower of Mercy.

[Surah al-Qalam (68): Verse 48]
“So be patient with your Lord’s decree, and do not be like the companion of the fish when he called out in distress.” (48)

Ibn ‘Abbās said: He forbade him to resemble the companion of the fish, who did not show the patience of the messengers of firm resolve.

A useful question arises here: the expression governing the temporal phrase “when he called out” cannot be the action being prohibited, since the meaning would then be: “Do not be like him in his calling out.” Yet Allah, Glorified is He, praised him for this call and stated that He saved him through it, saying:

21:87, 88 “And remember the man of the fish, when he went away in anger, thinking We would not constrain him. Then he called out in the depths of darkness: ‘There is no god but You. Glory be to You! I have indeed been among the wrongdoers.’ So We answered him and saved him from distress. And thus do We save the believers.”

Al-Tirmidhī and others relate that the Prophet, may Allah bless him and grant him peace, said: “The supplication of my brother, the man of the fish, when he supplicated in the belly of the fish—no distressed person ever invokes Allah with it without Allah relieving his distress—is: ‘There is no god but You. Glory be to You! I have indeed been among the wrongdoers.’”

He therefore could not have been forbidden to emulate him in this supplication, which was the call he addressed to