"Abdullah bin Sahl was found slain, and his brother, and two paternal uncles, Huwayysah and Huwayisaah, who were the paternal uncles of 'Abdullah bin Sahl, came to the Messenger of Allah. 'Abdur-Rahman started to speak, but the Messenger of Allah said: "Let the elders speak first." They said: "O Messenger of Allah, we found 'Abdullah bin Sahl slain in one of the dry wells of Khaibar." The prophet said: "Whom do you suspect? They said: "We suspect the Jews." He said: "Will you swear fifty oaths saying that the Jews killed him?" They said: "How can we swear an oath about something that we did not see?" He said: "Then can the Jews swear fifty oaths declaring that they did not kill him?" They said:"How can we accept their oaths, when they are Mushrikun?" So the Messenger of Allah paid the blood money himself.

(Sahih) Malik narrated this in Mursal from.