It is narrated from Sayyida Umm ‘Ammarah bint Ka‘b (may Allah be pleased with her) that the Noble Prophet (peace and blessings be upon him) came to her, so she presented food to him. The Prophet (peace and blessings be upon him) said to her, “You also eat.” She replied, “I am fasting.” The Noble Prophet (peace and blessings be upon him) said, “When food is eaten in the presence of a fasting person, the angels pray for him until they finish eating,” or he said, “until they finish the meal.”
The angels supplicate (make du'a) for him because he has performed an act greater than the angels; he refrained from it out of desire, solely for the pleasure of Allah Ta'ala, whereas the angels abstain from eating and drinking because they have no desire for food and drink in the first place. This hadith also proves that it is permissible to eat and drink in front of a fasting person (Wahidi).
From these ahadith, we learn of the noble character of the Messenger of Allah (sallallahu alayhi wa sallam), the evidence for visiting relatives, and also that when someone comes to visit, something should be presented to them to eat and drink as hospitality, and even if one is fasting oneself, one must still show hospitality to the guest.