It was narrated from Abu Malik Al-Ashja'i that his father said:
I prayed behind the Messenger of Allah (ﷺ) and he did not say the Qunut, and I prayed behind Abu Bakr and he did not say the Qunut, and I prayed behind Umar and he did not say the Qunut, and I prayed behind Uthman and he did not say the Qunut, and I prayed behind Ali and he did not say the Qunut. Then he said: O my son, this is an innovation.