Sahih Muslim Book 18, Hadith Number 4287.

Chapter : Entertainment of the Guest.

Abu Shuriah al-Khuza’i reported Allah’s Messenger (may peace be upon him) as saying: (The period of the entertainment of a guest is three days, and utmost kindness and courtesy is for a day and a night.=” It is not permissible for a Muslim to stay with, his brother until he makes him sinful. They said: Messenger of Allah, how he would make him sinful? He (the Holy Prophet) said: He stays with him (so long) that nothing is left with him to entertain him.