Sahih Bukhari Volume 7, Book 74, Hadith 5622

حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ أَبِي حَازِمِ بْنِ دِينَارٍ، عَنْ سَهْلِ بْنِ سَعْدٍ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أُتِيَ بِشَرَابٍ فَشَرِبَ مِنْهُ، وَعَنْ يَمِينِهِ غُلاَمٌ وَعَنْ يَسَارِهِ الأَشْيَاخُ‏.‏ فَقَالَ لِلْغُلاَمِ ‏"‏ أَتَأْذَنُ لِي أَنْ أُعْطِيَ هَؤُلاَءِ ‏"‏‏.‏ فَقَالَ الْغُلاَمُ وَاللَّهِ يَا رَسُولَ اللَّهِ لاَ أُوثِرُ بِنَصِيبِي مِنْكَ أَحَدًا‏.‏ قَالَ فَتَلَّهُ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي يَدِهِ‏.‏

Narrated By Sahl bin Sad : Allah's Apostle was offered something to drink. He drank of it while on his right was a boy and on his left were some elderly people. He said to the boy, "May I give these (elderly) people first?" The boy said, "By Allah, O Allah's Apostle! I will not give up my share from you to somebody else." On that Allah's Apostle placed the cup in the hand of that boy.