Musnad Ahmad 937:99

Waki’ narrated to us, Qudamah al-‘Amiri narrated to us, from Jasrah bint Dajajah, from Abu Dharr, that the Prophet (peace and blessings of Allah be upon him) recited this verse and repeated it until morning: "If You punish them, then indeed they are Your servants; and if You forgive them, then indeed You are the Exalted in Might, the Wise." [Al-Ma'idah: 118]