A companion of God’s Messenger reported him as saying, “When two people come together to issue an invitation accept that of the one who lives nearer you, but if one of them comes before the other accept the invitation of the one who comes first.”
‘Abdallah b. 'Umar reported God’s Messenger as saying, “He who does not accept an invitation which he receives has disobeyed God and His Messenger, and he who enters without an invitation enters as a thief and goes out as a raider.”
Ibn Mas'ud reported God’s Messenger as saying, “The food on the first day is a duty, that on the second is a sunna, but that on the third day is to make men hear of it; and if anyone makes men hear of what he does God will make him heard of” (i.e. will publish his hypocrisy on the day of resurrection).
Safina told that 'Ali b. Abu Talib prepared food for a man who was his guest, and Fatima said, "I wish we had invited God’s Messenger and he had eaten with us.” They invited him and when he came he put his hands on the side-posts of the door, but when he saw the figured curtain which had been put at the end of the house he went away. Fatima said she followed him and asked, “What turned you back, Messenger of God?” He replied, “It is not fitting for me or for any prophet to enter a house which is decorated.”
