Arabic text
عن جابر رضي الله عنه أن رسول الله صلى الله عليه وسلم قال: «رَحِمَ اللهُ رَجُلًا سَمْحًا إِذَا بَاعَ، وَإِذَا اشْتَرَى، وَإِذَا اقْتَضَى».
Translation
Jābir (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "May Allah have mercy on a man who is lenient when he sells, when he buys, and when he asks for repayment of the debt."
Explanation
The Prophet (may Allah's peace and blessings be upon him) supplicates for Allah's mercy upon everyone who is lenient and generous in his sale transactions. He does not overprice the product and treats the buyer in a good manner. And he is lenient and generous when he buys something, and he does not undervalue the product. And he is lenient and generous when he asks for repayment of the debts owed to him. He does not make things hard for the poor and needy; rather, he asks them for repayment in a kind and gentle manner and gives respite to those unable to pay.
Source: HadeethEnc.com