Musnad Abu Ya'la al-Mawsili 155:347

Hashim ibn al-Harith narrated to us, Ubaydullah ibn Amr narrated to us, from Zayd ibn Abi Unaysah, from Adi ibn Thabit, from Abu Hazim, from Abu Hurayrah, that the Messenger of Allah (peace and blessings of Allah be upon him) forbade that a man should bargain over the bargain of his brother. He forbade *al-tanajush* (bidding up the price without the intention to buy). He forbade meeting the caravans (before they reach the market). He forbade that a woman should ask for the divorce of her sister (to take her place). He forbade that water be withheld for fear that the pasture might be grazed. He forbade that a city dweller should sell for a bedouin. And whoever gives a *minhah* (a gift of a milking animal), it goes out with charity and returns with charity, its morning milking and its evening milking.