Imam al-Sha'bi (may Allah have mercy on him) said: A slain man was found in the territory of Hamdan, and the case was brought to Sayyiduna Umar (may Allah be pleased with him). They swore fifty oaths about it: "We did not kill him, nor do we know (the killer)." Then he (may Allah be pleased with him) imposed the blood money on them as a fine and said: "O people of Hamdan, by your oaths you have been cleared of his blood, but I cannot let the blood of a Muslim go to waste."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب القسامة / 16449