Sahih Muslim 3805
صحيح مسلم#3805SahihAbu Huraira (Allah be pleased with him) reported:Two types of trarisactions have been forbidden (by the Holy Prophet), al-Mlulamasa and al-Munabadha. As far as Mulamasa transaction is concerned, it is that every one of them (the parties entering into transaction) should touch the garment of the other without careful consideration, and al-Munabadha is that every one of them should throw his cloth to the other and one of them should not see the cloth of his friend
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 21:5