Musnad Abu Ya'la al-Mawsili 148:24

Musa ibn Muhammad ibn Hayyan al-Basri narrated to us, Abd al-A’la narrated to us, Hisham narrated to us, from Abd Allah ibn Dihqan, from Anas ibn Malik: That the Messenger of Allah (may Allah bless him and grant him peace) forbade that a man should eat with his left hand or drink with his left hand.