"At the time of the Messenger of Allah we used to be called Samasir (brokers). The Messenger of Allah came to us when we were selling and called us by a name that was better than that. He said: 'O merchants (Tujjar), this selling involves lies and (false) oaths, so mix some charity with it.'" (Using translation from Nasāʾī 3797)
كُنَّا نُسَمَّى السَّمَاسِرَةَ فَأَتَانَا النَّبِيُّ ﷺ وَنَحْنُ نَبِيعُ فَسَمَّانَا بِاسْمٍ هُوَ أَحْسَنُ لَنَا مِنِ اسْمِنَا فَقَالَ «يَا مَعْشَرَ التُّجَّارِ إِنَّ هَذَا الْبَيْعَ يَحْضُرُهُ الْحَلِفُ وَالْكَذِبُ فَشُوبُوا بَيْعَكُمْ بِصَدَقَةٍ»