Musnad Abu Ya'la al-Mawsili 130:36

'Abd al-A'la narrated to us, 'Uthman ibn 'Umar narrated to us, Shu'bah narrated to us, from 'Abd al-'Aziz, who said: I heard Anas saying: "Eat the pre-dawn meal (suhur), for indeed there is blessing in the pre-dawn meal."