Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) narrates: On the occasion of the Battle of Khaybar, qasamah (oaths over an unresolved killing) took place concerning a killing. It came about in this way: a man of the Ansar, one of the Companions of the Prophet (peace and blessings be upon him), went missing at night. The Ansar came and said: "Our companion has been found weltering in his blood (killed)." The Prophet (peace and blessings be upon him) said: "Do you know who killed him?" They replied: "No, except that the Jews must have killed him." The Prophet (peace and blessings be upon him) said: "Choose fifty men from among them, and let them swear this oath in the name of Allah; then take the blood money from them." And they did so.
Al-Bazzar recorded it. Its chain contains Abd al-Rahman bin Yamin, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الديات / 10735