Language:
كتاب المساقاة
42  
Distribution of Water
(10)
Chapter: The owner of a tank or a leather water-container
(10)
باب مَنْ رَأَى أَنَّ صَاحِبَ الْحَوْضِ وَالْقِرْبَةِ أَحَقُّ بِمَائِهِ
Sahih al-Bukhari 2366

Narrated Sahl bin Sa`d:

Once a tumbler (full of milk or water) was brought to Allah's Messenger (ﷺ) who drank from it, while on his right side there was sitting a boy who was the youngest of those who were present, and on his left side there were old men. The Prophet (ﷺ) asked, "O boy ! Do you allow me to give (the drink) to the elder people (first)?" The boy said, "I will not prefer anybody to have my share from you, O Allah's Apostle!" So, he gave it to the boy.

حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا عَبْدُ الْعَزِيزِ، عَنْ أَبِي حَازِمٍ، عَنْ سَهْلِ بْنِ سَعْدٍ ـ رضى الله عنه ـ قَالَ أُتِيَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِقَدَحٍ فَشَرِبَ وَعَنْ يَمِينِهِ غُلاَمٌ، هُوَ أَحْدَثُ الْقَوْمِ، وَالأَشْيَاخُ عَنْ يَسَارِهِ قَالَ ‏ "‏ يَا غُلاَمُ أَتَأْذَنُ لِي أَنْ أُعْطِيَ الأَشْيَاخَ ‏"‏‏.‏ فَقَالَ مَا كُنْتُ لأُوثِرَ بِنَصِيبِي مِنْكَ أَحَدًا يَا رَسُولَ اللَّهِ‏.‏ فَأَعْطَاهُ إِيَّاهُ‏.‏
Reference : Sahih al-Bukhari 2366
In-book reference : Book 42, Hadith 14
USC-MSA web (English) reference : Vol. 3, Book 40, Hadith 554
  (deprecated numbering scheme)