Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that he heard the Messenger of Allah (peace and blessings be upon him) say: "Swearing oaths makes goods sell, but it wipes out the profit."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10406
Sayyiduna Abu Qatadah al-Ansari (may Allah be pleased with him) heard the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Beware of swearing many oaths in selling, for it brings increase, but then the blessing is wiped out."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10410
Sayyiduna Abu Dharr (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "There are three to whom Allah will not look with mercy, nor will He speak to them, and for them is a severe punishment." The narrator says: I said: O Messenger of Allah (peace and blessings be upon him), who are these people? They are the ruined and the losers. He said: "The one who reminds others of his favours, the one who arrogantly lets his lower garment drag on the ground, and the one who promotes his merchandise by swearing false oaths."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10411
Sayyiduna Qays bin Abi Gharazah (may Allah be pleased with him) says: In the time of the Messenger of Allah (peace and blessings be upon him) we used to buy and sell in the markets, and we called ourselves brokers. But the Prophet (peace and blessings be upon him) gave us a name better than that; he (peace and blessings be upon him) said: "O company of merchants, falsehood and idle talk occur during trade, so mix it with charity."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10412
Sayyiduna Qays bin Abi Gharazah (may Allah be pleased with him) says: We used to buy and sell in the markets and called ourselves brokers. He (peace and blessings be upon him) said: "O company of merchants, swearing is customary in these markets of yours, so mix it with charity, or with something of charity."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10413
Isma'il bin Ubayd bin Rifa'ah bin Rafi' al-Zuraqi (may Allah have mercy on him) narrates from his father, from his grandfather (may Allah be pleased with him), that he went out with the Messenger of Allah (peace and blessings be upon him) to the prayer ground in Madinah. He (peace and blessings be upon him) saw people buying and selling with one another, so he (peace and blessings be upon him) said: "O company of merchants!" They responded to the Messenger of Allah (peace and blessings be upon him) and raised their eyes towards him (peace and blessings be upon him). Then he (peace and blessings be upon him) said: "On the Day of Resurrection the merchants will be raised as wrongdoers, except the one who feared Allah, did good and spoke the truth."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10414
Abd al-Rahman bin Shibl (may Allah be pleased with him), who is one of the Companions of the Prophet (peace and blessings be upon him), says: I heard the Messenger of Allah (peace and blessings be upon him) say: "The merchants are wrongdoers." A man said: Has Allah not made trade lawful? He (peace and blessings be upon him) said: "Certainly, but they swear oaths and so become sinners."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10415
Nafi' narrates from Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "The truthful, trustworthy Muslim merchant will be with the martyrs on the Day of Resurrection."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10416