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كتاب المساقاة
42  
Distribution of Water
(1)
Chapter: Giving water in charity, or as a gift, and whoever thinks that giving water in charity, or as a gift or by way of a testament is permissible, whether it is divided or not
(1)
بَابٌ في الشُّرْبِ، وَمَنْ رَأَى صَدَقَةَ الْمَاءِ وَهِبَتَهُ وَوَصِيَّتَهُ جَائِزَةً، مَقْسُومًا كَانَ أَوْ غَيْرَ مَقْسُومٍ
Sahih al-Bukhari 2352

Narrated Az-Zuhri:

Anas bin Malik said, that once a domestic sheep was milked for Allah's Messenger (ﷺ) while he was in the house of Anas bin Malik. The milk was mixed with water drawn from the well in Anas's house. A tumbler of it was presented to Allah's Messenger (ﷺ) who drank from it. Then Abu Bakr was sitting on his left side and a bedouin on his right side. When the Prophet (ﷺ) removed the tumbler from his mouth, `Umar was afraid that the Prophet (ﷺ) might give it to the bedouin, so he said. "O Allah's Messenger (ﷺ)! Give it to Abu Bakr who is sitting by your side." But the Prophet (ﷺ) gave it to the bedouin, who was to his right and said, "You should start with the one on your right side."

حَدَّثَنَا أَبُو الْيَمَانِ، أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ حَدَّثَنِي أَنَسُ بْنُ مَالِكٍ ـ رضى الله عنه ـ أَنَّهَا حُلِبَتْ لِرَسُولِ اللَّهِ صلى الله عليه وسلم شَاةٌ دَاجِنٌ وَهْىَ فِي دَارِ أَنَسِ بْنِ مَالِكٍ، وَشِيبَ لَبَنُهَا بِمَاءٍ مِنَ الْبِئْرِ الَّتِي فِي دَارِ أَنَسٍ، فَأَعْطَى رَسُولَ اللَّهِ صلى الله عليه وسلم الْقَدَحَ فَشَرِبَ مِنْهُ، حَتَّى إِذَا نَزَعَ الْقَدَحَ مِنْ فِيهِ، وَعَلَى يَسَارِهِ أَبُو بَكْرٍ وَعَنْ يَمِينِهِ أَعْرَابِيٌّ فَقَالَ عُمَرُ وَخَافَ أَنْ يُعْطِيَهُ الأَعْرَابِيَّ أَعْطِ أَبَا بَكْرٍ يَا رَسُولَ اللَّهِ عِنْدَكَ‏.‏ فَأَعْطَاهُ الأَعْرَابِيَّ الَّذِي عَلَى يَمِينِهِ، ثُمَّ قَالَ ‏ "‏ الأَيْمَنَ فَالأَيْمَنَ ‏"‏‏.‏
Reference : Sahih al-Bukhari 2352
In-book reference : Book 42, Hadith 2
USC-MSA web (English) reference : Vol. 3, Book 40, Hadith 542
  (deprecated numbering scheme)