Sahih Muslim 1612a

It is prohibited for one to take the property of another except with his consent, particularly the unjust seizure of land because it usually lasts for a long time. Hence, the Prophet (may Allah's peace and blessings be upon him) said that whoever unjustly seizes a piece of land of any size would be severely punished on the Day of Judgment; his neck would be long and thick enough to be encircled with the seized land down the seven earths in retribution for what he did to the owner of that land.

This threat does not apply to the use of public lands without seizing or occupying them. In his book Al-Mughni, Ibn Qudāmah said: "With regard to streets, roadways and alleys, no one has the right to develop that land (such as building on it and other activities by which it would become someone’s property), whether they are wide or narrow, and whether that results in less space for people or not, because such spaces are shared by Muslims and their interests are connected to them; so it is more akin to their mosques.

It is permissible to benefit from such spaces by sitting there to buy and sell, in a way that does not cause any annoyance to anyone or harm the passers-by, because people in all countries and at all times have approved of people doing that, without denouncing it; and because it is a kind of permissible usage, provided that it does not result in any harm. So it is allowed, like passing through.