عَنْ أَبِي سَعِيدٍ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ إِذَا أَتَى أَحَدُكُمْ حَائِطًا فَأَرَادَ أَنْ يَأْكُلَ فَلْيُنَادِ يَا صَاحِبَ الْحَائِطِ ثَلَاثًا فَإِنْ أَجَابَهُ وَإِلَّا فَلْيَأْكُلْ وَإِذَا مَرَّ أَحَدُكُمْ بِإِبِلٍ فَأَرَادَ أَنْ يَشْرَبَ مِنْ أَلْبَانِهَا فَلْيُنَادِ يَا صَاحِبَ الْإِبِلِ أَوْ يَا رَاعِيَ الْإِبِلِ فَإِنْ أَجَابَهُ وَإِلَّا فَلْيَشْرَبْ وَالضِّيَافَةُ ثَلَاثَةُ أَيَّامٍ فَمَا زَادَ فَهُوَ صَدَقَةٌ
. Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: When any of you enters someone’s orchard and wishes to eat from there, he should call out: O owner of the orchard! He should call out three times. If the owner responds, then that is fine; otherwise, he may eat from the orchard. And when any of you passes by camels and wishes to drink the milk of the she-camels, he should call out: O owner of the camels! Or: O herder of the camels! If he responds, then that is correct; otherwise, he may milk and drink. Hospitality is for three days; anything beyond that is charity upon the guest.