Musannaf Ibn Abi Shayba 13:748

Abu Bakr narrated to us, he said: Hafs ibn Sulayman narrated to us, from Isma'il, from al-Hasan, who said: If one emancipates his slave, whether a little or a lot, he is emancipated. And if he divorces his wife by a finger or more than that, she is divorced.