Soon after arriving in Madinah, the Prophet ﷺ visited the city's souqs (marketplaces). The Ansar, the Muslims native to Madinah, were mostly farmers rather than traders. The main souqs were run by the Jewish tribes in their settlements outside the center of Madinah. The Prophet ﷺ disapproved of the deceptive practices he saw there, and he said to the Muslims, "This is not a souq for you."
He then went back to his masjid. With his own feet he marked out lines in the sand for a new souq to the west of the masjid, and said, "This shall be your souq. So let it not be diminished, and let no one tax the people in it." The souq had two simple rules. All trade had to stay within the marked lines, and no one paid any tax or fee to trade there.
He also banned interest and praised honesty in trade. He forbade cheating, lying, false oaths, and hiding defects in goods. He also forbade anyone living in Madinah from acting as an agent for a Bedouin who came to sell his goods. A local agent knew the market and could take advantage of an outsider who did not.
Because the Muslim souq was wholly independent of the Jewish-run markets, when the Jewish tribes were later expelled from Madinah one by one and their souqs collapsed, it left no effect on the Muslim economy.
Other events recorded in 1 AH. Their order within the year is not established; use the storyline above for the sequence.
This is not a souq for you. ... This shall be your souq. So let it not be diminished, and let no one tax the people in it.
Said first at the marketplaces the Jewish tribes ran outside Madinah, where the Prophet ﷺ saw practices he disapproved of; he then returned to the masjid and marked out this new site as the Muslims' own souq.
Whoever cheats is not of us.
Said to a date seller the Prophet ﷺ found hiding rotten dates beneath the good ones at the top of his sacks.