Musnad Ahmad 27:438

'Abd al-Razzaq narrated to us, Malik narrated to us, from Ibn Shihab, from Abu Bakr ibn 'Ubayd Allah, from Ibn 'Umar, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "When one of you eats, let him eat with his right hand, and when he drinks, let him drink with his right hand, for the devil eats with his left hand and drinks with his left hand."