Sahih Bukhari, Chapter: Witr Prayer

I asked Anas bin Malik about the Qunut. Anas replied, "Definitely it was (recited)". I asked, "Before bowing or after it?" Anas replied, "Before bowing." I added, "So and so has told me that you had informed him that it had been after bowing." Anas said, "He told an untruth (i.e. "was mistaken," according to the Hijazi dialect). Allah's Apostle recited Qunut after bowing for a period of one month." Anas added, "The Prophet sent about seventy men (who knew the Quran by heart) towards the pagans (of Najd) who were less than they in number and there was a peace treaty between them and Allah's Apostles (but the Pagans broke the treaty and killed the seventy men). So Allah's Apostle recited Qunut for a period of one month asking Allah to punish them."