Yahya related to me from Malik from Muhammad ibn Yahya ibn Habbanand from Abu'z-Zinad from al-Araj from Abu Hurayra that the Messengerof Allah, may Allah bless him and grant him peace, forbade mulamasaand munabadha.Malik said, "Mulamasa is when a man can feel agarment but is not allowed to unfold it or examine what is in it, orhe buys by night and does not know what is in it. Munabadha is that aman throws his garment to another, and the other throws his garmentwithout either of them making any inspection. Each of them says, 'thisis for this. 'This is what is forbidden of mulamasa and munabadha."Malik said that selling bundles with a list of their contentswas different from the sale of the cloak concealed in a bag or thecloth folded up and such things. What made it different was that itwas a common practice and it was what people were familiar with, andwhat people had done in the past, and it was still among the permittedtransactions and trading of people in which they saw no harm becausein the sale of bundles with a list of contents without undoing them,an uncertain transaction was not intended and it did not resemblemulamasa.
USC-MSA web (English) reference: Book 31, Hadith 76
Arabic reference: Book 31, Hadith 1366