حَدَّثَنِي مَالِكٌ، عَنِ ابْنِ شِهَابٍ، أَنَّهُ أَخْبَرَهُ ‏.‏ أَنَّ رَجُلاً اعْتَرَفَ عَلَى نَفْسِهِ بِالزِّنَا عَلَى عَهْدِ رَسُولِ اللَّهِ صلى الله عليه وسلم وَشَهِدَ عَلَى نَفْسِهِ أَرْبَعَ مَرَّاتٍ فَأَمَرَ بِهِ رَسُولُ اللَّهِ صلى الله عليه وسلم فَرُجِمَ ‏.‏ قَالَ ابْنُ شِهَابٍ فَمِنْ أَجْلِ ذَلِكَ يُؤْخَذُ الرَّجُلُ بِاعْتِرَافِهِ عَلَى نَفْسِهِ

Malik related to me that Ibn Shihab informed him that a manconfessed that he had committed adultery in the time of the Messengerof Allah, may Allah bless him and grant him peace, and he testifiedagainst himself four times, so the Messenger of Allah, may Allah blesshim and grant him peace, gave the order and he was stoned. Ibn Shihab said, "Because of this a man is to be taken for his ownconfession against himself." Translation Not Available

Book Ref: Muwatta Imam Malik Book 41 Hadith 1506
Web Ref:  Muwatta Imam Malik Book 41 Hadith 4