I heard Messenger of Allah (ﷺ) say: Swearing produces a ready sale for a commodity but blots out the blessing. The narrator Ibn al-Sarh said: "for earning". He also narrated this tradition from Sa'id b. al-Musayyab on the authority of Abu Hurairah from the Prophet (ﷺ).
Sunan Abi Dawud Book 23, Hadith 10
← Previous Hadith On the authority of his father: I heard the Messenger of Allah (ﷺ) say in the Farewell Pilgrimage: "Lo, all claims to usury of the pre-Islamic period have been abolished. You shall have your capital sums, deal not unjustly and you shall not be dealt with unjustly.

Lo, all claims for blood-vengeance belonging to the pre-Islamic period have been abolished. The first of those murdered among us whose blood-vengeance I remit is al-Harith ibn AbdulMuttalib, who suckled among Banu Layth and killed by Hudhayl."

He then said: O Allah, have I conveyed the message? They said: Yes, saying it three times. He then said: O Allah, be witness, saying it three times.

Sunan Abi Dawud Book 23, Hadith 9 Next Hadith → I and Makhrafah al-Abdi imported some garments from Hajar, and brought them to Mecca. The Messenger of Allah (ﷺ) came to us walking, and after he had bargained with us for some trousers, we sold them to him. There was a man who was weighing for payment. The Messenger of Allah (ﷺ) said to him: Weigh out and give overweight.

Sunan Abi Dawud Book 23, Hadith 11