Musnad Ahmad 30:608

'Abd al-Razzaq narrated to us, Dawud ibn Qays informed us, from Musa ibn Yasar, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "When the servant of one of you prepares his food for him, then brings it to him having attended to its heat and its smoke, let him seat him with him so that he may eat. If the food is scarce and little, let him place in his hand a morsel or two."