Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says: Ukaz, Majannah and Dhu al-Majaz were markets in the time of Ignorance (Jahiliyyah). When Islam came, people regarded trading in them as sinful, so Allah Almighty revealed this verse: "There is no sin upon you if you seek the bounty of your Lord (in the seasons of Hajj)." [Surah al-Baqarah: 198]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 8658
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says: In the early Hajj seasons, people used to buy and sell at Mina, Arafah and the market of Dhu al-Majaz during the days of Hajj; then they became fearful of trading while in the state of ihram, so Allah Almighty revealed this verse: "There is no sin upon you in seeking the bounty of your Lord" [Surah al-Baqarah: 198], that is: there is no sin upon you if you seek the bounty of your Lord (in the seasons of Hajj). Ubayd bin Umayr says that Ibn Abbas (may Allah be pleased with them both) used to recite this verse in this way in the mushaf.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 8659