Khalaf ibn Hisham narrated to us, saying: ‘Isa ibn Maymun narrated to us, from Mu‘awiyah ibn Qurrah, who said: I entered upon al-Hasan while he was reclining on his couch. I said, “Abu Sa‘id, which deeds are most beloved to Allah?” He answered, “The prayer offered in the depths of the night while people are asleep.” I asked, “Which form of fasting is best?” He said, “Fasting on a hot summer day.” I asked, “Which emancipation of a slave is most virtuous?” He replied, “The one most valued by its owners and commanding the highest price.” I then asked, “What is your view of warʿ (scrupulous piety)?” He said, “That is the foundation of the entire matter.”