It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that the Messenger (peace and blessings be upon him) said: When you enter an orchard and intend to eat, call the owner of the orchard three times. If he comes, very good; otherwise, eat alone but do not exceed the limits. Similarly, when you pass by a shepherd, call him three times. If he comes, very good; otherwise, you may drink his milk as long as you do not exceed the limits. And the Prophet (peace and blessings be upon him) said: Hospitality is for three days; whatever is beyond that is charity. And the Prophet (peace and blessings be upon him) said: Hospitality is for three days; whatever is beyond that is charity.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11812
Hadith Gradingحکم دارالسلام:حديث ضعيف دون قوله: الضيافة ثلاثة أيام فما بعده فصدقة، فهو صحيح. على بن عاصم الواسطي ضعيف، وسماعه من الجريري بعد الاختلاط