From Sahih Muslim (Hadith 6917):
This hadith has been transmitted on the authority of Ibn Abi Laili but with this addition:" 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
Reference: Muslim 6917