Abu Shuraih Khuwailid bin 'Amr Al-Khuza'i (May Allah be pleased with him) reported:
I heard Messenger of Allah ﷺ saying, "He who believes in Allah and the Last Day, should accommodate his guest according to his right." He was asked: "What is his right, O Messenger of Allah?" He ﷺ replied: "It is (to accommodate him) for a day and a night, and hospitality extends for three days, and what is beyond that is charity."
[Al-Bukhari and Muslim].
In Muslim it is added: Messenger of Allah ﷺ said, "It is not permissible for a Muslim to stay so long with his brother till he makes him sinful." He was asked: "O Messenger of Allah, how can he make him sinful?" He replied, "He prolongs his stay with him till nothing is left with the host to entertain him (guest)."
وعن أبي شريح خويلد بن عمرو الخزاعي رضي الله عنه قال: سمعت رسول الله صلى الله عليه وسلم يقول: "من كان يؤمن بالله واليوم الآخر فليكرم ضيفه جائزته" قالوا: وما جائزته يا رسول الله صلى الله عليه وسلم قال: "يومه وليلته. والضيافة ثلاثة أيام، فما كان وراء ذلك فهو صدقة عليه” ((متفق عليه)) .
وفي ((رواية لمسلم)): "لا يحل لمسلم أن يقيم عند أخيه حتى يؤثمة" قالوا: يا رسول الله ، وكيف يؤثمه؟ قال: "يقيم عنده ولا شيء له يقريه به".