I prayed behind the Messenger of Allah ﷺ and he did not perform qunut. I prayed behind Abu Bakr and he did not perform qunut. I prayed behind Umar and he did not perform qunut. I prayed behind Uthman and he did not perform qunut. I prayed behind Ali and he did not perform qunut.Then he said, "My son, it is an innovation."
أخبرنا قتيبة عن خلف وهو ابن خليفة
صليت خلف رسول الله ﷺ فلم يقنت وصليت خلف أبي بكر فلم يقنت وصليت خلف عمر فلم يقنت وصليت خلف عثمان فلم يقنت وصليت خلف علي فلم يقنت ثم قال يا بني إنها بدعة
No references are available.
[Its isnad is sahih] Tirmidhi narrated it, Prayer, chapter on what has been said about abandoning qunut, hadith no. 402, 403, and Ibn Majah, Establishing Prayers, chapter on what has been said about qunut in Fajr prayer, hadith no. 1241, from the hadith of Abu Malik Saad bin Tariq, through this same chain. Tirmidhi said, "Hasan sahih." It is also found in Al-Kubra, hadith no. 667.