The Book of Oaths and Vows
35/22. Chapter:
Swearing Oaths And Lying When One Does Not Believe In What He Is Swearing About
Sunan an-Nasai
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ يَزِيدَ، عَنْ سُفْيَانَ، عَنْ عَبْدِ الْمَلِكِ، وَعَاصِمٍ، وَجَامِعٍ، عَنْ أَبِي وَائِلٍ، عَنْ قَيْسِ بْنِ أَبِي غَرَزَةَ، قَالَ كُنَّا نَبِيعُ بِالْبَقِيعِ فَأَتَانَا رَسُولُ اللَّهِ صلى الله عليه وسلم وَكُنَّا نُسَمَّى السَّمَاسِرَةَ فَقَالَ " يَا مَعْشَرَ التُّجَّارِ " . فَسَمَّانَا بِاسْمٍ هُوَ خَيْرٌ مِنِ اسْمِنَا ثُمَّ قَالَ " إِنَّ هَذَا الْبَيْعَ يَحْضُرُهُ الْحَلِفُ وَالْكَذِبُ فَشُوبُوهُ بِالصَّدَقَةِ " .
It was narrated that Qais bin Abi Gharazah said: "We used to sell in Al-Baqi, and the Messenger of Allah came to us. We used to be called Samasir (brokers) but he said: 'O merchants!' And called us by a name that was better than our name. Then he said: 'This selling involves (false) oaths and lies, so mix some charity with it.'"
Reference : Sunan an-Nasa'i 3798In-book reference : Book 35, Hadith 38English translation : Vol. 4, Book 35, Hadith 3829