Musnad Ahmad 32:1760

'Affan narrated to us, Hammad ibn Salamah narrated to us, he said: 'Abd al-'Aziz ibn Suhayb narrated to us, from Anas ibn Malik, from the Prophet, peace and blessings of Allah be upon him, who said: "Eat the pre-dawn meal (suhur), for indeed in the pre-dawn meal there is blessing."