Musannaf Ibn Abi Shaybah 29664 — How much testimony is valid in a case

Al-Mas'udi said that al-Qasim said: Two men from Kufah came to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) and found him leaving the House of Allah. They said: "O Commander of the Believers, our cousin has been killed, and we are exactly equal in the claim to his blood." He remained silent towards the two of them, and then said: "Bring two just witnesses against the one who killed him, and I will have retaliation granted to you from him."