Musannaf Ibn Abi Shayba 9:695

Muhammad ibn Bishr narrated to us, from Mis'ar, who said: Al-Hasan informed me, from Sa'd, from Ibn Abi Mulaykah, that Ibn Abbas was asked about *al-'azl* (coitus interruptus). He then called a slave girl of his and said: "I practiced *'azl* with you yesterday."