The Messenger of Allah (swt), peace be upon him, said:
"Do not envy anyone, do not increase the price to anyone, do not hate anyone, do not turn your back on anyone and not inferiorize anyone in the trade; but are servants of Allah and brothers (among you). Muslims are brothers to one another, do not oppress, not abandon, do not lie and do not despise. Piety is here (and he pointed to his chest three times). It is enough sin for a man to despise his fellow Muslim. The blood, property and honor of a Muslim can not be violated by another Muslim. "(Muslim)