Allaah says (interpretation of the meaning): “O you who believe! When the call is proclaimed for the salaat (prayer) on the day of Friday (Jumu’ah prayer), come to the remembrance of Allaah and leave off business (and every other thing), that is better for you if you did but know!” [al-Jumu’ah 62:9].
Some people continue trading in their stores and in front of the mosque even after the second call to prayer; those who buy from them also share in their guilt, even if they only buy a siwaak (natural toothbrush). According to the soundest opinion, this sale is invalid. Some owners of restaurants, bakeries and factories force their employees to work at the time of Jumu’ah prayers; even if this leads to an apparent increase in earnings, they will ultimately be losers in reality. The employee is obliged to act in accordance with the teaching of the Prophet (peace and blessings of Allaah be upon him): “There is no obedience to a created being if it involves disobedience to Allaah.” (Reported by Imaam Ahmad, 1/129; Ahmad Shaakir said: its isnaad is saheeh, no. 1065).
