Narrated Ibn `Abbas:`Ukaz, Majanna and Dhul-Majaz were marketplaces in the Pre-Islamic period of ignorance. When Islam came, Muslims felt that marketing there might be a sin. So, the Divine Inspiration came: "There is no harm for you to seek the bounty of your Lord (in the seasons of Hajj)." (2.198) Ibn `Abbas recited the Verse in this way.
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ كَانَتْ عُكَاظٌ وَمِجَنَّةُ وَذُو الْمَجَازِ أَسْوَاقًا فِي الْجَاهِلِيَّةِ، فَلَمَّا كَانَ الإِسْلاَمُ فَكَأَنَّهُمْ تَأَثَّمُوا فِيهِ فَنَزَلَتْ {لَيْسَ عَلَيْكُمْ جُنَاحٌ أَنْ تَبْتَغُوا فَضْلاً مِنْ رَبِّكُمْ } فِي مَوَاسِمِ الْحَجِّ، قَرَأَهَا ابْنُ عَبَّاسٍ.
Bukhari
Sales and Trade • Hadith 4