Musannaf Ibn Abi Shayba 18:720

Abu Bakr narrated to us, he said: Abd al-Rahim ibn Sulayman narrated to us, from Muhammad ibn Ishaq, from Aban ibn Salih, from Mujahid, from Ibn Mas’ud, he said: He used to say: The blood money (diyah) of the People of the Book is like the blood money of the Muslim.