Ibrahim (may Allah have mercy on him) says: "Blood money in all camels, whether young or old, was fixed at 120 dirhams per camel, by the weight of six, and this comes to 10,000 dirhams." It was said to Sharik bin Abdullah (may Allah have mercy on him): A Muslim man grappled with a man of the enemy and struck him, but the blow hit a Muslim man. Sharik (may Allah have mercy on him) said that Ibn Ishaq (may Allah have mercy on him) said: A man of ours grappled with a man of the enemy and struck him, but it hit a man of ours and sliced off his face, so that it fell onto his eyebrows, nose, beard and chest; in this case the ruling Sayyiduna Uthman (may Allah be pleased with him) gave was 12,000 dirhams, and the dirham at that time was of the weight of six.
Imam al-Shafi'i (may Allah have mercy on him) says that many people of the Hijaz, such as Ata, Makhul, Amr bin Shu'ayb (may Allah have mercy on them) and others, have reported from Sayyiduna Umar (may Allah be pleased with him) that the blood money is 12,000 dirhams. I do not know of anyone in the Hijaz who differed on this from him, nor from Sayyiduna Uthman (may Allah be pleased with him). Among those who hold that the blood money is 12,000 dirhams, Sayyiduna Ibn Abbas (may Allah be pleased with them both), Sayyiduna Abu Hurayrah (may Allah be pleased with him) and Sayyidah Aishah (may Allah be pleased with her) are worth mentioning, and Ikrimah (may Allah have mercy on him) has narrated from the Prophet (peace and blessings be upon him) a ruling on blood money of "12,000 dirhams".
Imam al-Shafi'i (may Allah have mercy on him) says: I asked Muhammad bin al-Hasan (may Allah have mercy on him): Do you say that the blood money is 12,000 dirhams of the weight of six? He said: No. I said: Then from where have you accepted this from Sayyiduna Umar (may Allah be pleased with him), when Sayyiduna Umar (may Allah be pleased with him) judged by it but you do not? The Shaykh says: This report from Sayyiduna Umar (may Allah be pleased with him) is munqati' (broken), and likewise from Sayyiduna Uthman (may Allah be pleased with him); and there is the hadith of Amr bin Shu'ayb from his father from his grandfather, which we have narrated connected (mawsul) from Sayyiduna Umar (may Allah be pleased with him), and along with it the hadith of Sayyiduna Ibn Abbas (may Allah be pleased with them both). And Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16188