The Messenger of Allah ﷺ said, "Hospitality is for three days. Whatever is given beyond that is charity."
قال رسول الله ﷺ الضيافة ثلاث فما زاد على ذلك فهو صدقة.
Ahmad narrated it (11325) from Abdul-Razzaq, and it is in his Musannaf (20528), "Muamar reported to us, from Jareeri, from Abu Nadra, from Abu Saeed Khudri, who said" and he mentioned it. Its isnad is sahih. Jareeri is Saeed bin Iyas, who became confused in his later years, but Muamar bin Rashid heard from him before that confusion occurred.