It is recommended to accept the invitation of one who invites to food even if there is no particular occasion

Imam al-Shafi'i (may Allah have mercy on him) said: "It has reached us that the Messenger of Allah (peace and blessings be upon him) said: 'If a foreleg (of a goat) were given to me as a gift, I would certainly accept it, and if I were invited to (a meal of) a trotter (of a goat), I would certainly accept.'"

Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "By the One in whose hand is my soul! If I were invited to eat a trotter, I would accept, and if a foreleg or shoulder were given to me as a gift, I would accept." But Waki' did not mention the words "By the One in whose hand is my soul".

Sayyiduna Anas bin Malik (may Allah be pleased with him) said that Sayyiduna Abu Talhah (may Allah be pleased with him) said to Sayyidah Umm Sulaym (may Allah be pleased with her): "I heard the voice of the Messenger of Allah (peace and blessings be upon him), and it was weak; I recognised hunger in it. Do you have anything?" Sayyidah Umm Sulaym (may Allah be pleased with her) said: "Yes." She brought out some loaves of barley bread, then Sayyidah Umm Sulaym (may Allah be pleased with her) took out her head-covering, wrapped the bread in part of it, tucked it under my arm and draped part of it over me, and sent me to the Messenger of Allah (peace and blessings be upon him). He said: When I took it, the Messenger of Allah (peace and blessings be upon him) was in the mosque with people. I stood there, or I greeted him, and the Messenger of Allah (peace and blessings be upon him) said to me: "Has Abu Talhah sent you?" I said: "Yes." He (peace and blessings be upon him) said: "For food?" I said: "Yes." The Messenger of Allah (peace and blessings be upon him) said to his companions: "Get up." He said: He (peace and blessings be upon him) set off and I walked ahead of them until I came and informed Sayyiduna Abu Talhah (may Allah be pleased with him). Sayyiduna Abu Talhah (may Allah be pleased with him) said: "O Umm Sulaym! The Messenger of Allah (peace and blessings be upon him) has come with the people, and we do not have food to feed them." She said: "Allah and His Messenger know best." Sayyiduna Anas bin Malik (may Allah be pleased with him) said: Sayyiduna Abu Talhah (may Allah be pleased with him) went and met the Prophet (peace and blessings be upon him), then the Messenger of Allah (peace and blessings be upon him) and Sayyiduna Abu Talhah (may Allah be pleased with him) both entered the house, and the Messenger of Allah (peace and blessings be upon him) said: "O Umm Sulaym! Bring what you have." She brought those loaves. Sayyiduna Anas (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) gave the order and the loaves were broken into pieces, and Sayyidah Umm Sulaym (may Allah be pleased with her) squeezed her skin of ghee over them as a condiment. Then the Prophet (peace and blessings be upon him) said over it what Allah willed, and then said: "Let ten men in." So Sayyiduna Abu Talhah (may Allah be pleased with him) called ten men; they ate until they were full and left. Then he (peace and blessings be upon him) said: "Call ten more." They too ate their fill, and in this way all the people ate their fill, and the people numbered seventy or eighty.

Yahya bin Yahya (may Allah have mercy on him) said: I read to Imam Malik (may Allah have mercy on him), and he mentioned a hadith like it, (in which it says) that she tucked it under my garment and gave me some of it as it was.
(b) Sa'd bin Sa'id narrates from Sayyiduna Anas bin Malik (may Allah be pleased with him), and in it there is the addition that when Umm Sulaym (may Allah be pleased with her) came to that food after all the people had eaten and left, the food was just as it had been.

Sayyiduna Anas bin Malik (may Allah be pleased with him) said that a tailor invited the Prophet (peace and blessings be upon him) to a meal. Sayyiduna Anas (may Allah be pleased with him) said: I also went with the Messenger of Allah (peace and blessings be upon him) to eat, and barley bread and a broth containing gourd and pieces of dried meat were placed before the Messenger of Allah (peace and blessings be upon him). Sayyiduna Anas (may Allah be pleased with him) said: I saw the Messenger of Allah (peace and blessings be upon him) searching for the gourd around the sides of the dish. Since that day I too have loved gourd.

Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) said to his Companions (may Allah be pleased with them): "Get up, Jabir (may Allah be pleased with him) has prepared a feast."
(b) Hajjaj bin al-Sha'ir narrates a long hadith from Abu Asim (may Allah have mercy on them both), and the context of this hadith indicates that this invitation to food was other than a wedding.

Sayyiduna Jabir bin Abdullah al-Ansari (may Allah be pleased with him) said: On the day of the Trench, when the people were afflicted with severe hunger, I said to my wife: "Do you have anything so that I may invite the Prophet (peace and blessings be upon him)?" She said: "We have only a sa' of barley." Sayyiduna Jabir (may Allah be pleased with him) said: I said to her: "Grind it," and I slaughtered a young goat that we had. He said: She finished just as I finished. I invited the Prophet (peace and blessings be upon him); I said: "O Messenger of Allah! We had a sa' of barley and a young goat, which we have slaughtered." Sayyiduna Jabir (may Allah be pleased with him) said: the Prophet (peace and blessings be upon him) announced among his Companions (may Allah be pleased with them): "Come! Jabir has prepared a feast." Sayyiduna Jabir (may Allah be pleased with him) said: I walked ahead of the people and came to my wife, and she said: "Do not disgrace us today before the Messenger of Allah (peace and blessings be upon him)." Sayyiduna Jabir (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) arrived and said: "Put down your cooking pot." He said: They put the meat in it, and he (peace and blessings be upon him) put some of his saliva in it and supplicated for blessing, then said: "Tell the women who bake bread to bake." They began baking bread. Sayyiduna Jabir (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) said: "Come in ten at a time." He (peace and blessings be upon him) was serving (the food) to them, and they kept eating until the last of them had come, and our cooking pot and our dough were just as they had been.

Sayyiduna Abdullah bin Busr (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) passed by my father while he (peace and blessings be upon him) was riding his white mule. My father came and took hold of the reins of his mule and said: "Stay with us." He said: He (peace and blessings be upon him) stopped with us, and dates and sawiq were brought. He (peace and blessings be upon him) was eating the dates, placing the stones on the back of his index finger or middle finger, or on both, and then throwing them away. He said: Then they prepared food for him (peace and blessings be upon him), and he (peace and blessings be upon him) ate. After that a cup of milk or sawiq was brought; he (peace and blessings be upon him) drank, then gave it to the one on his (peace and blessings be upon him) right. When he (peace and blessings be upon him) intended to set off or depart, they said: "Supplicate for us." So the Messenger of Allah (peace and blessings be upon him) said: 'Allahumma barik lahum fima razaqtahum, waghfir lahum warhamhum' (O Allah, bless them in what You have provided them, forgive them and have mercy on them).