Sahih Bukhari | Volume 3 | Hadith Number 354

Narrated by Abu Said
Allah's Apostle forbade the selling by Munabadha, i.e. to sell one's garment by casting it to the buyer not allowing him to examine or see it. Similarly he forbade the selling by Mulamasa. Mulamasa is to buy a garment, for example, by merely touching it, not looking at it.