It is narrated from Sayyiduna Abu Karimah (may Allah be pleased with him) that he heard the Prophet (peace and blessings be upon him) say: "Hosting a guest for one night is a right upon every Muslim, and when a guest spends the morning in someone's courtyard, it is a right or a debt in his favour; if he wishes he may claim it, and if he wishes he may leave it."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17756