Musnad Ahmad 30:1777

'Abd al-Razzaq narrated to us, he said: Sufyan informed us, from Ibn Abi Layla, from 'Ata', from Abu Hurayrah, he said: The Messenger of Allah, may Allah bless him and grant him peace, said: "Eat the suhur (pre-dawn meal), for indeed there is blessing in the suhur."