Language:
كتاب الإجارة
37  
Hiring
(13)
Chapter: One who employs himself to carry loads on his back and then gives in charity from his wages, and (what is said about) the wages of porters
(13)
باب مَنْ آجَرَ نَفْسَهُ لِيَحْمِلَ عَلَى ظَهْرِهِ. ثُمَّ تَصَدَّقَ بِهِ وَأُجْرَةِ الْحَمَّالِ
Sahih al-Bukhari 2273

Narrated Abu May' id Al-Ansari:

Whenever Allah's Messenger (ﷺ) ordered us to give in charity we would go to the market and work as porters to earn a Mudd (two handfuls) (of foodstuff) but now some of us have one-hundred thousand Dirhams or Diners. (The sub-narrator) Shaqiq said, "I think Abu Mas`ud meant himself by saying (some of us) .

حَدَّثَنَا سَعِيدُ بْنُ يَحْيَى بْنِ سَعِيدٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا الأَعْمَشُ، عَنْ شَقِيقٍ، عَنْ أَبِي مَسْعُودٍ الأَنْصَارِيِّ ـ رضى الله عنه ـ قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم إِذَا أَمَرَ بِالصَّدَقَةِ انْطَلَقَ أَحَدُنَا إِلَى السُّوقِ فَيُحَامِلُ فَيُصِيبُ الْمُدَّ، وَإِنَّ لِبَعْضِهِمْ لَمِائَةَ أَلْفٍ، قَالَ مَا نُرَاهُ إِلاَّ نَفْسَهُ‏.‏
Reference : Sahih al-Bukhari 2273
In-book reference : Book 37, Hadith 13
USC-MSA web (English) reference : Vol. 3, Book 36, Hadith 473
  (deprecated numbering scheme)