Answered by Shaykh Faraz Rabbani
The clause is part of a contract to be given to a barber. The owner of the barber shop does not want the barber to be hired only to quit the shop after some time, take the shop’s clients, and go to another shop, possibly the barber’s previous shop. The manager of the shop therefore wants to put a clause in the agreement to effectively disable the worker from working in a 4-mile radius of the owner’s shop. The clause is planned to stay in effect for 1 year after the worker’s quitting or leaving the barber shop.
Walaikum assalam wa rahmatullah,
This follows the fiqh of non-compete clauses, see below.
Wassalam,