Hadith 6:941
Abu Bakr narrated to us, he said: Abu Bakr al-Hanafi narrated to us, from Kathir ibn Zayd, from al-Muttalib ibn Abdullah ibn Hantab, he said: When Uthman ibn Maz'un died, the Messenger of Allah (peace and blessings of Allah be upon him) buried him in al-Baqi'. And he said to a man: "Go to that rock and bring it to me, so that I may place it at his grave, so that I may recognize it by it."
حدثنا أبو بكر قال ثنا أبو بكر الحنفي عن كثير بن زيد عن المطلب بن عبد الله بن حنطب قال لما مات عثمان بن مظعون دفنه رسول الله صلى الله عليه وسلم بالبقيع وقال لرجل اذهب إلى تلك الصخرة فأتني بها حتى اضعها عند قبره حتى اعرفه بها