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.
Sahih Muslim Book 21, Hadith 26
← Previous Hadith 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.

Sahih Muslim Book 21, Hadith 25 Next Hadith → Jabir (Allah be pleased with him) reported a similar hadith from Allah's Apostle (ﷺ) through another chain of transmitters.

Sahih Muslim Book 21, Hadith 27