Musnad Ahmad 31:538

Khalaf ibn al-Walid narrated to us, al-Mubarak narrated to us, from al-Hasan, from Abu Sa’id al-Khudri, who narrated it from the Prophet, may Allah bless him and grant him peace: That dates were brought to him, and their quality pleased him. They said: "O Messenger of Allah, we took a sa’ for two sa’s in order to feed him." He disliked that and forbade it.