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.'"
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 " .
Nesai
The Book of Oaths and Vows • Hadith 3798