Musannaf Ibn Abi Shayba 23:29

Affan narrated to us, he said: Hammad bin Zayd narrated to us, from Ali bin Zayd, from Umm Muhammad, that a man said to Aisha: "What is faith?" She said: "Shall I explain in detail or summarize?" He said: "No, rather summarize." She said: "Whoever is gladdened by his good deed and saddened by his evil deed, then he is a believer."