Musnad Ahmad 30:1325

'Abd al-Samad narrated to us, Hisham narrated to us, from Yahya, from Abu Salamah, from Abu Hurairah, who said: "By Allah, I am the closest of you in prayer to the Messenger of Allah." Abu Hurairah used to perform Qunut in the final Rak'ah of the last Isha prayer and the morning prayer after he would say: "Allah hears those who praise Him," so he would supplicate for the believers and curse the disbelievers.