Sahih al-Bukhari 2351
Narrated Sahl bin Sa`d:
A tumbler (full of milk or water) was brought to the Prophet (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, will you allow me to give it (i.e. the rest of the drink) to the old 
men?" The boy said, "O Allah's Messenger (ﷺ)! I will not give preference to anyone over me to drink the rest 
of it from which you have drunk." So, the Prophet (ﷺ) gave it to him.
حَدَّثَنَا سَعِيدُ بْنُ أَبِي مَرْيَمَ، حَدَّثَنَا أَبُو غَسَّانَ، قَالَ حَدَّثَنِي أَبُو حَازِمٍ، عَنْ سَهْلِ بْنِ سَعْدٍ ـ رضى الله عنه ـ قَالَ أُتِيَ النَّبِيُّ صلى الله عليه وسلم بِقَدَحٍ فَشَرِبَ مِنْهُ، وَعَنْ يَمِينِهِ غُلاَمٌ أَصْغَرُ الْقَوْمِ، وَالأَشْيَاخُ عَنْ يَسَارِهِ فَقَالَ ‏
"‏ يَا غُلاَمُ أَتَأْذَنُ لِي أَنْ أُعْطِيَهُ الأَشْيَاخَ ‏"‏‏.‏ قَالَ مَا كُنْتُ لأُوثِرَ بِفَضْلِي مِنْكَ أَحَدًا يَا رَسُولَ اللَّهِ‏.‏ فَأَعْطَاهُ إِيَّاهُ‏.‏