Mishkat al-Masabih #2032

He reported God’s messenger as saying, “Is any of you incapable of reciting a third of the Qur’ān in a night?” On being asked how they could recite a third of the Qur’ān he replied. “‘Say, He is God, One’ (Qur’ān, 112) is equivalent to a third of the Qur’ān.” Muslim transmitted it, and Bukhārī transmitted it from Abū Sa'īd.