Sahih Muslim
The Book of Prayers (Kitab Al-Salat)
Book Number: 004 / Hadith Number: 1914
Abu Huraira reported that the Apostle of Allah (may peace be upon him) used to recite in the dawn prayer on Friday:" Alif-Lam-Mim, Tanzil" in the first rak'ah, and in the second one:" Surely there came over the man a time when he was nothing that could be mentioned."