Musannaf Ibn Abi Shayba 7:370

12514. Abd al-Rahim narrated to us, from Dawud ibn Abi Hind, from Amir, who said: A man asked Ibn Abbas about a man who vowed to slaughter his son. He said: "He should slaughter one hundred camels, just as Abd al-Muttalib ransomed his son with them." Another said: "A ram, just as Ibrahim ransomed his son Ishaq." I asked Masruq, and he said: "This is from the promptings of Satan; there is no expiation for it."