Musnad Abu Ya'la al-Mawsili 151:77

Bishr narrated to us, Sharik narrated to us, from Abu Hamzah, from Ibrahim, from Alqamah, from Ibn Mas’ud, who said: The Prophet, peace and blessings of Allah be upon him, only performed Qunut for a month, supplicating therein against a tribe from the tribes of Banu Sulaym who were Usayyah; they disobeyed Allah and His Messenger. Then he did not perform Qunut after that.