Musnad Ahmad 304:4

Sufyan ibn 'Uyaynah narrated to us, from al-Walid ibn Kathir, from Wahb ibn Kaysan, from 'Umar ibn Abi Salamah, who said: The Prophet (may Allah bless him and grant him peace) said to me: "O boy, mention the name of Allah, eat with your right hand, and eat from what is in front of you." He said: That remained my way of eating ever since, and my hand used to wander [all over the plate].