Maliks Muwatta
Maliks Muwatta Book 007, Hadith Number 001.
Hadith Section/Book: Maliks Muwatta Maliks Muwatta Book 07. Tahajjud
Section : Concerning Prayer in the Night.
Yahya related to me from Malik from Muhammad ibn al-Munkadir from Said ibn al-Jubayr that a man who has approval (as a relater of hadith), told him that A'isha, the wife of the Prophet, may Allah bless him and grant him peace, said, "If a man prays in the night and sleep overcomes him during it, Allah writes for him the reward of his prayer, and his sleep is sadaqa for him."
Yahya related to me from Malik from Muhammad ibn al-Munkadir from Said ibn al-Jubayr that a man who has approval (as a relater of hadith), told him that A'isha, the wife of the Prophet, may Allah bless him and grant him peace, said, "If a man prays in the night and sleep overcomes him during it, Allah writes for him the reward of his prayer, and his sleep is sadaqa for him."