Kaab bin Ujra entered the masjid while Abdul-Rahman ibn Umm Hakam was delivering the sermon sitting down. He said, "Look at this vile man, delivering the sermon sitting down, when Allah Most High has said, 'But when they saw some merchandise or amusement, they rushed off to it and left you standing'" [Jumuah 62:11].
دخل كعب بن عجرة المسجد وعبد الرحمن ابن أم الحكم يخطب قاعدا، فقال: انظروا إلى هذا الخبيث يخطب قاعدا، وقال الله تعالى: {وإذا رأوا تجرة أو لهوا أنفضوا إليها وتركوك قائما}
Muslim narrated it in the Book of Jumuah (864) through several routes from Muhammad bin Jafar, who said, Shuba narrated to us from Mansur, from Amr bin Mura, from Abu Ubayda, and he mentioned it.Surah Jumuah contains the refutation of three claims made by the Jews.The first is their pride in being the People of the Book, while the Arabs had no book, so Allah likened them to a donkey in His saying, "The example of those who were entrusted with the Torah and then did not uphold it is like that of a donkey who carries volumes of books" [Jumuah 62:5].The second is their claim that they were the allies and beloved ones of Allah, to the exclusion of others, so Allah refuted their claim by saying, "Then wish for death, if you should be truthful" [Jumuah 62:6].The third is their pride in being the people of the Sabbath, which the Muslims had no equivalent to, so Allah legislated the day of Jumuah for the Muslims, saying, "O you who have believed, when the call is made for prayer on the day of Jumuah, then proceed to the remembrance of Allah" [Jumuah 62:9].It has been established, as mentioned before, that the Jews and Christians went astray, so Allah guided the Muslims to the day of Jumuah.Jumuah has specific rulings, among them.1 - The prohibition of buying and selling after the call to the Jumuah prayer, the call meant here being the one that occurs when the preacher ascends the pulpit. By analogy, this extends to anything that distracts from attending Jumuah and turning to listen to the sermon, even if it was originally permissible.2 - Whoever refrains from buying and selling after the call, Allah will provide for him from where he does not expect, for Allah described Himself as the best of providers.3 - The legislation of the two sermons, and it is obligatory in both of them to give reminders and recite the Quran.4 - After the completion of the prayer, one who is engaged in trade is permitted to go about his trade, or if he is an employer he may go to his work, though this is not obligatory, because a command that comes after a prohibition indicates permissibility rather than obligation.