Abu Huraira (Allah be pleased with him) reported it directly from Allah's Apostle (ﷺ)
The townsman'should not sell for a man from the desert (with a view to taking advantage of his ignorance of the market conditions of the city). And Zuhair reported from the Prophet (ﷺ) that he forbade the townsman to sell on behalf of the man from the desert.
Ibn 'Abbas (Allah be pleased with them) reported Allah's Messenger (ﷺ) as saying
The riders (carrying merchandise) should not be met in the way, and townsman should not sell for a man of the desert. The narrator reported. I said to Ibn 'Abbas: What do these words really imply-" The townsman for the man of the desert"? He said: That he should work as a broker on his behalf.
Jabir (Allah be pleased with him) reported Allah's Messenger (ﷺ) as saying
The townsman should not sell for a man from the desert, leave the people alone, Allah will give them provision from one another. Yahya reported it with a slight change of words.
Jabir (Allah be pleased with him) reported a similar hadith from Allah's Apostle (ﷺ) through another chain of transmitters.
Anas b. Malik (Allah be pleased with him) reported
We were forbidden that a townsman should sell for a man of the desert, even if he is his brother or father.
Anas b. Malik (Allah be pleased with him) said
We were forbidden that a townsman should sell for a man of the desert.