The Prophet ﷺ was delivering the sermon standing on Friday when a caravan arrived from Syria, and the people turned away toward it until only twelve men were left. Then this verse in Surah Jumuah was revealed, "And when they see some merchandise or amusement, they rush off to it and leave you standing" [Jumuah 62:11].
أن النبي ﷺ كان يخطب قائما يوم الجمعة، فجاءت عير من الشام، فانفتل الناس إليها، حتى لم بيق إلا ا حدثنا عشر رجلا. فنزلت هذه الآية التي في الجمعة: {وإذا رأوا تجرة أو لهوا أنفضوا إليها وتركوك قائما} [الجمعة ١١].
Bukhari narrated it in the Jumuah chapter (936) and Muslim in the Jumuah chapter (863), both through Husayn bin Abdul-Rahman, from Salim bin Abu Jaad, from Jabir bin Abdullah, who related the hadith. The wording given is Muslim's, and Bukhari's wording is similar.Muslim also narrated with his chain from Kaab bin Ujra, who said, He entered the masjid while Abdul-Rahman bin Umm Hakam was delivering the sermon sitting down, and he said, "Look at this vile man! He delivers the sermon sitting down, while Allah Most High has said, "and when they saw a trade or amusement they rushed off to it and left you standing" [Jumuah 62:11]."