" Ali said: Ever since I heard this (supplication) from Allah's Apostle (ﷺ), I never abandoned it. It was said to him, Not even in the night of Siffin (battle of Siffin)? He sad: Yes, not even in the night of Siffin,"
Sahih Muslim Book 48, Hadith 110
← Previous Hadith This hadith has been narrated on the authority of Shu'ba with the same chain of transmitters but. with a slight variation of wording.

Sahih Muslim Book 48, Hadith 109 Next Hadith → You would not be able to get a servant from us. May I not direct you to what is better than the servant for you? Recite Subhaana Allah thirty-three times, al- Hamdu li-Allah thirty-three times and Allah-o-Akbar thirty-four times as you go to bed. This hadith has been narrated on the authority of Suhail with the same chain of transmitters.

Sahih Muslim Book 48, Hadith 111