Musnad Abu Ya'la al-Mawsili 42:80

Muhammad ibn 'Abbad narrated to us, Abu Sa'id narrated to us, from Sadaqah ibn al-Rabi', from 'Umarah ibn Ghaziyyah, from 'Abd al-Rahman ibn Abi Sa'id—I think he said from his father (Abu 'Abd Allah was doubtful)—he said: I heard the Prophet, may Allah bless him and grant him peace, while he was upon the wooden steps (minbar), saying: "That which is little and suffices is better than that which is much and distracts."