(67) باب الصَّوْمِ يَوْمَ النَّحْرِ
Narrated Abu Huraira:
Two fasts and two kinds of sale are forbidden: fasting on the day of `Id ul Fitr and `Id-ul-Adha and the kinds of sale called Mulamasa and Munabadha. (These two kinds of sale used to be practiced in the days of Pre-Islamic period of ignorance; Mulamasa means when you touch something displayed for sale you have to buy it; Munabadha means when the seller throws something to you, you have to buy it.)
Reference: Sahih al-Bukhari 1993
In-book reference: Book 30, Hadith 99
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 31, Hadith 213