صحيح مسلم

Sahl b. Abu Hathma and Rafi' b. Khadij reported that 'Abdullah b. Sahl b. Zaid and Muhayyisa b. Mas'ud b. Zaid went out and as they reached Khaibar they were separated. Then Muhayyisa found 'Abdullah b. Sahl having been killed. He buried him, and then came to Allah's Messenger (ﷺ). They were Huwayyisa b. Mas'ud and 'Abd al-Rahman b. Sahl, and he (the latter one) was the youngest of the people (those three who had come to seek an interview with the Holy Prophet) began to talk before his Companions (had spoken). Thereupon Allah's Messenger (ﷺ) said: The eldest one (eldest in regard to age should speak). So he kept quiet, and his companions (Muhayyisa and Huwayyisa) began to speak, and he ('Abd al Rahman) spoke along with them and they narrated to Allah's Messenger (ﷺ) the murder of 'Abdullah b. Sahl. Thereupon he said to them: Are you prepared to take fifty oaths so that you may be entitled (to blood-wit) of your companion (or your man who has murdered)? They said: How can we take an oath on a matter which we have not witnessed? He (the Holy Prophet) said: Then the Jews will exonerate themselves by fifty oaths. They said: How can we accept the oaths of people who are unbelievers? When Allah's Messenger (ﷺ) saw that, he himself paid his blood-wit.