"I said to my father: 'O my father! You offered Salat behind Allah's Messenger (S), Abu Bakr, Umar, Uthman, and Ali bin Abi Talib here in Al-Kufah for about five years. Did they say the Qunut?' He said: 'It is a newly invented matter my son.'"
Jami` at-Tirmidhi Book 2, Hadith 255