In the time of the Messenger of Allah ﷺ we used to be called brokers, but the Prophet ﷺ came upon us one day, and called us by a better name than that, saying: O company of merchants, unprofitable speech and swearing takes place in business dealings, so mix it with sadaqah (alms).  

كُنَّا فِي عَهْدِ رَسُولِ اللَّهِ ﷺ نُسَمَّى السَّمَاسِرَةَ فَمَرَّ بِنَا رَسُولُ اللَّهِ ﷺ فَسَمَّانَا بِاسْمٍ هُوَ أَحْسَنُ مِنْهُ فَقَالَ يَا مَعْشَرَ التُّجَّارِ إِنَّ الْبَيْعَ يَحْضُرُهُ اللَّغْوُ وَالْحَلِفُ فَشُوبُوهُ بِالصَّدَقَةِ  

"Lying and swearing have a place on i." 'Abd Allah al-Zuhri said: "Unprofitable speech and lying."  

يَحْضُرُهُ الْكَذِبُ وَالْحَلِفُ وَقَالَ عَبْدُ اللَّهِ الزُّهْرِيُّ اللَّغْوُ وَالْكَذِبُ