Musnad Ahmad 30:2943

'Abd al-Malik narrated to us, he said: Hisham narrated to us, from Yahya, from Abu Salamah, he said: Abu Hurairah used to say: "I will surely bring you closer to the prayer of the Messenger of Allah, may Allah bless him and grant him peace." So Abu Hurairah would perform Qunut in the final Rak'ah of the Dhuhr prayer, the final 'Isha' prayer, and the Subh (morning) prayer after he said: "Allah hears those who praise Him," and he would supplicate for the believers and curse the disbelievers.