Sayyiduna Abu Hurayrah (may Allah be pleased with him) says: By Allah, I will lead you in a prayer like that of the Messenger of Allah (peace and blessings be upon him). Then he (may Allah be pleased with him) would recite qunut in the second rak'ah of the morning prayer after saying 'Sami'a Allahu liman hamidah' (Allah has heard the one who praised Him), in which he would supplicate for the believers and supplicate against the disbelievers.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3121