Language:
كتاب الجهاد والسير
56  
Fighting for the Cause of Allah (Jihaad)
(71)
Chapter: The service, during holy battles
(71)
باب فَضْلِ الْخِدْمَةِ فِي الْغَزْوِ
Sahih al-Bukhari 2888

Narrated Anas:

I was in the company of Jabir bin `Abdullah on a journey and he used to serve me though he was older than I. Jarir said, "I saw the Ansar doing a thing (i.e. showing great reverence to the Prophet (ﷺ) ) for which I have vowed that whenever I meet any of them, I will serve him."

حَدَّثَنَا مُحَمَّدُ بْنُ عَرْعَرَةَ، حَدَّثَنَا شُعْبَةُ، عَنْ يُونُسَ بْنِ عُبَيْدٍ، عَنْ ثَابِتٍ الْبُنَانِيِّ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه ـ قَالَ صَحِبْتُ جَرِيرَ بْنَ عَبْدِ اللَّهِ، فَكَانَ يَخْدُمُنِي‏.‏ وَهْوَ أَكْبَرُ مِنْ أَنَسٍ قَالَ جَرِيرٌ إِنِّي رَأَيْتُ الأَنْصَارَ يَصْنَعُونَ شَيْئًا لاَ أَجِدُ أَحَدًا مِنْهُمْ إِلاَّ أَكْرَمْتُهُ‏.‏
Reference : Sahih al-Bukhari 2888
In-book reference : Book 56, Hadith 103
USC-MSA web (English) reference : Vol. 4, Book 52, Hadith 138
  (deprecated numbering scheme)