Muslim

Abu Hurairah (RA) 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 Holy Prophet (ﷺ) that he forbade the townsman to sell on behalf of the man from the desert.

Ibn 'Abbas (RA) 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 (RA) : 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.

Yahya ibn Yahya al-Tamimi narrated to us, Abu Khaythamah informed us, from Abu al-Zubayr, from Jabir. And Ahmad ibn Yunus narrated to us, Zuhayr narrated to us, Abu al-Zubayr narrated to us, from Jabir, who said: The Messenger of Allah, peace and blessings be upon him, said: "Let not a townsman sell for a Bedouin. Leave the people, so that Allah may provide for some of them through others." However, in Yahya's narration, it is: "is provided for."

Jabir (RA) reported a similar hadith from Allah's Apostle (ﷺ) through another chain of transmitters.

Anas bin Malik (RA) reported: We were forbidden that a townsman should sell for a man of the desert, even if he is his brother or father.

Muhammad ibn al-Muthanna narrated to us, Ibn Abi Adi narrated to us, from Ibn ‘Awn, from Muhammad, from Anas.
And Ibn al-Muthanna narrated to us, Mu‘adh narrated to us, Ibn ‘Awn narrated to us, from Muhammad, who said: Anas ibn Malik said:
“We were forbidden that a townsman should sell for a Bedouin.”