Sahih Muslim 1018
Sahih Muslim · Book 12: The Book of Zakat · Carrying goods for payment and giving charity out of one's wages, and the stern prohibition of belittling the one who gives something small in charity
This hadith has been narrated by Shu'ba with the same chain of transmitters and in the hadith transmitted by Sa'id b. al Rabi (the words are):
وَحَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ ، حَدَّثَنِي سَعِيدُ بْنُ الرَّبِيعِ ، ح وَحَدَّثَنِيهِ إِسْحَاقُ بْنُ مَنْصُورٍ ، أَخْبَرَنَا أَبُو دَاوُدَ ، كِلاَهُمَا عَنْ شُعْبَةَ ، بِهَذَا الإِسْنَادِ . وَفِي حَدِيثِ سَعِيدِ بْنِ الرَّبِيعِ قَالَ كُنَّا نُحَامِلُ عَلَى ظُهُورِنَا .
" We used to carry loads on our backs."