صحيح مسلم

Bushair b. Yasar al-Ansari reported on the authority of Sahl b. Abu Hathma al-Ansari that some men (of his tribe went to Khaibar, and they were separated from one another, and they found one of them slain. The rest of the hadith is the same. And it was said in this connection: Allah's Messenger (may peace be him) did not approve of his blood go waste. He paid blood-wit of one hundred camels of Sadaqa.