Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: In the time of the Messenger of Allah, a man was killed, and the Prophet (peace and blessings be upon him) fixed his diyah at 12000, and this is (what is referred to in) the saying of Allah Almighty: "And they resented nothing" [Surah al-Tawbah: 74] (to the end of) the verse.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16177
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said that the Prophet (peace and blessings be upon him) "ruled 12000 for the diyah."
Muhammad bin Maymun said: He (Sufyan) said "from Ibn Abbas" to us only once; most of the time he used to say: from Ikrimah, from the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16178
Abu Bakr bin Muhammad bin Amr bin Hazm (may Allah have mercy on him) narrates from his father (may Allah have mercy on him), and he from his grandfather (may Allah be pleased with him), that in the letter which the Prophet (peace and blessings be upon him) wrote concerning blood money (diyah) there was: "Upon the people of gold are 1000 dinars."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16179
Sayyidah Aishah (may Allah be pleased with her) relates that once she was praying when a snake appeared close by, so at the order of Sayyidah Aishah (may Allah be pleased with her) it was killed. Sayyidah Aishah (may Allah be pleased with her) saw in a dream that she was being told: "Have you killed a Muslim who had come to listen to the Qur'an? Pay his blood money." So Sayyidah Aishah (may Allah be pleased with her) paid his blood money of 12000 dirhams.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16182
Sayyiduna Abu Hurayrah (may Allah be pleased with him) says: Every day I recite glorifications (tasbih) equal in number to my own blood money of 12000 dirhams.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16183