Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Bukhari :: Book 5 :: Volume 59 :: Hadith 414
Narrated 'Abdul Aziz:
Anas said, "The Prophet sent seventy men, called Al-Qurra 'for some purpose. The two groups of Bani Sulaim called Ri'l and Dhakwan, appeared to them near a well called Bir Ma'una. The people (i.e. Al-Qurra) said, 'By Allah, we have not come to harm you, but we are passing by you on our way to do something for the Prophet.' But (the infidels) killed them. The Prophet therefore invoked evil upon them for a month during the morning prayer. That was the beginning of Al Qunut and we used not to say Qunut before that." A man asked Anas about Al-Qunut, "Is it to be said after the Bowing (in the prayer) or after finishing the Recitation (i.e. before Bowing)?" Anas replied, "No, but (it is to be said) after finishing the Recitation."