What is the meaning of the Prophet's (peace be upon him) prohibition "that a city dweller sell for a Bedouin, even if he is his brother by father and mother," and why is this prohibition, and how does it apply to city dwellers, and does it mean that the people of a country do not sell to another country? And what is the meaning of the prohibition of receiving (Talaqqi), and of a city dweller buying for a Bedouin, and of a man outbidding his brother's bargain, and of Najash (collusive bidding) and Tasriya (tying up a she-camel's udder), and why is each of these prohibited?

The prohibition of various types of sales is due to the harms that result from them, including: talaqqī al-rukbān (intercepting riders), which is buying goods from them before they enter the city and become aware of prices, thereby harming the seller and the general public; and bay‘ al-ḥāḍir li’l-bādī (the city-dweller selling for the desert-dweller), which is when a rural or nomadic person brings goods intending to sell them at market price, but a city-dweller approaches him to sell them gradually for a higher price. The scholars differ in their interpretation of this, whether it extends to include those who are not desert-dwellers or is limited to camel-owners due to their ignorance of prices.

As for as-sawm (undermining a sale), its form is to say after the price has been settled: "Return it, and I will sell you something better for the same price," or "something similar for less."

And an-najsh (bid-rigging) is to increase the price of an item by someone who does not intend to buy it, so that another person falls into it.

And at-taṣriyah (milk retention) is to refrain from milking an animal so that milk accumulates in its udder, making its milk appear abundant.

Scholars have differed in understanding the meaning of these aḥādīth and the reasons for their rulings. For detailed information, one should refer to books of fiqh and their commentaries.