(Imām Bukhārī narrates): Musaddad narrated the hadith to us, he said: Abdul Wahid narrated the hadith to us, he said: Asim narrated the hadith to us, he said:
I asked Hazrat Anas bin Malik (Allāh be pleased with him) about Qunut, he said: Qunut is (legislated), I asked: Before ruku or after ruku? He said: Before ruku. Asim said: Such and such a person narrated to me from you that you said it was after ruku. Hazrat Anas said: He spoke falsely. The Messenger of Allāh ﷺ recited Qunut after ruku for only one month. I think that he ﷺ had sent a group towards the polytheists who were called Qurra, they were about seventy persons, these polytheists were other than those polytheists with whom the Messenger of Allāh ﷺ had a treaty of peace. The Messenger of Allāh ﷺ kept making the supplication of harm against them for one month.
Reference: Sahih Al Bukhari 1002