Hadith: Whoever believes in Allah and the Last Day let him honor his guest with his due reward. They said: O Messenger of Allah, what is his due reward? He said: "A day and a night (of excellent accommodation) and hospitality is for three days, and whatever is beyond that is charity offered to him."

عن أبي شُريح خُويلد بن عمرو الخزاعي عن النبي صلى الله عليه وسلم أنه قال: «مَنْ كَان يُؤمِن بِاللهِ وَاليَومِ الآخِرِ فَلْيُكْرِم ضَيفَه جَائِزَتَه»، قَالوا: وما جَائِزَتُهُ؟ يَا رسول الله، قال: «يَومُهُ ولَيلَتُهُ، والضِّيَافَةُ ثَلاَثَةُ أَيَّامٍ، فَمَا كَانَ وَرَاءَ ذَلك فَهُوَ صَدَقَةٌ عَلَيه». وفي رواية: «لا يَحِلُّ لِمُسْلِمٍ أَنْ يُقِيمَ عِنْدَ أَخِيهِ حَتَّى يؤْثِمَهُ» قالوا: يَا رَسول الله، وَكَيفَ يُؤْثِمَهُ؟ قال: «يُقِيمُ عِندَهُ ولاَ شَيءَ لَهُ يُقرِيهِ بهِ».
[صحيح] - [الرواية الأولى متفق عليها، والرواية الثانية رواها مسلم]

Abu Shurayh Khuwaylid ibn ‘Amr al-Khuzā‘i reported that the Prophet (may Allah's peace and blessings be upon him) said: "Whoever believes in Allah and the Last Day let him honor his guest with his due reward." They said: "O Messenger of Allah, what is his due reward?" He said: "A day and a night (of excellent accommodation), and hospitality is for three days, and whatever is beyond that is charity offered to him." In another version: "It is not lawful for a guest to stay (for long) at the home of his brother to the point that he causes him to sin." They said: "O Messenger of Allah, how does he cause him to sin?" He said: "He overstays with him till he has nothing to serve to him."
[Authentic hadith] - [Al-Bukhari and Muslim with its two versions]

Explanation

The Hadīth of Abu Shurayh al-Khuzā‘i (may Allah be pleased with him) highlights the principle of honoring and serving the guest. He reported that the Prophet (may Allah's peace and blessings be upon him) said: "Whoever believes in Allah and the Last Day let him honor his guest." And this is meant to encourage and urge honoring the guest, and it means that honoring the guest is a sign of belief in Allah and the Last Day and perfect faith in Allah and the Last Day. Some of the ways one can honor guests: meeting him with a cheerful face, saying good words to him, and offering him food for three days. On the first day, he should be generous to him as much as he can, and on the remaining days he serves him from what he can afford without going beyond what is normal, so that he does not burden the guest or himself. After the three days, it is considered charity. If he wishes to (continue) he may, and if not he may desist. Regarding his statement: "Let him honor his guest with his due reward for a day and a night, and hospitality is three days", the scholars said that 'reward' means giving much care to the guest for a day and a night and present to him as much kindness and goodness as he can. As for the second and third days, he feeds him what is available with him, and he does not exceed what is customary. What is beyond three days is charity and favor. If he wishes he may do so and if he wishes he may desist. In the version of Muslim: "And it is not lawful for him to stay at his home to the point that he causes him to sin", meaning it is not permissible for the guest to stay at the host's home more than three days until he causes him to fall into sin, as he may backbite him for overstaying, say indirect speech that may offense him, or have unlawful suspicions of him. All this applies in case the guest stays beyond three days without an invitation from the host. The standard of honoring the guest differs depending on the condition of the guest; a noble person should be honored with what is befitting for him, a middle-class person should be honored with what is befitting for him, and there are others who are below that.