Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 44
Narrated Ibn 'Abbas:
'Ukaz, Mijanna and Dhul-Majaz were markets during the Pre-islamic Period. They (i.e. Muslims) considered it a sin to trade there during the Hajj time (i.e. season), so this Verse was revealed:-- "There is no harm for you if you seek of the Bounty of your Lord during the Hajj season." (2.198)