Al-Matalib al-'Aliyah 1428 — The etiquette of selling

The narrator said: Muhammad bin Ubayd informed us; al-Mukhtar (who is Ibn Qani' al-Tammar) narrated to us from Abu Matar, who said: I came out of the mosque and suddenly found a man calling out behind me: "Raise your lower garment." Then the narrator mentioned the rest of the hadith: it was Sayyiduna Ali (may Allah be pleased with him) (who was calling). The narrator said: Then he reached the camel market and said: "Trade, but do not swear oaths, for an oath sells the goods but wipes out the blessing." Then he came to a date seller and saw a maidservant there weeping. He asked: "What is the matter with you?" She said: "This man sold me dates for a dirham, but my master has refused to accept them." He said: "Take these back and give her her dirham, for she has no authority of her own (that is, she is not independent)." The shopkeeper seemed to want to refuse, so I said to him: "Do you know who this is?" He said: "No." I said: "This is Ali, the Commander of the Believers!" So he immediately took back his dates and gave her her dirham. Then he (may Allah be pleased with him) passed by the date sellers and said: "Feed the poor, and your earnings will increase and grow."