Sunan Abu Dawud, Book 38 (Kitab al Hudud, ie. Prescribed Punishments), Number 4434:
:Narrated Abdullah Ibn Umar: A group of Jews came and invited the Apostle of Allah (peace_be_upon_him) to Quff. So he visited them in their school. They said: Abu Qasim, one of our men has committed fornication with a woman; so pronounce judgment upon them. They placed a cushion for the Apostle of Allah (peace_be_upon_him) who sat on it and said: Bring the Torah. It was then brought. He then withdrew the cushion from beneath him and placed the Torah on it saying: I believed in thee and in Him Who revealed thee. He then said: Bring me one who is learned among you. Then a young rabbi<ref>Islamic tradition says the young rabbi was Abdallah ibn Saba. Modern historiographic research identifies this rabbi as Heman ibn Shallum, the 38th Jewish Exilarch (de jure), who was a young child at the time. Heman ibn Shallum was deposed in 642CE in by Caliph 'Umar in favor of Bostanai.</ref> was brought..."