(10) باب مَنْ رَأَى أَنَّ صَاحِبَ الْحَوْضِ وَالْقِرْبَةِ أَحَقُّ بِمَائِهِ
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.
Reference: Sahih al-Bukhari 2366
In-book reference: Book 42, Hadith 14
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 40, Hadith 554