Sahih Muslim | Book 10 | Hadith Number 3612

Narrated by Abu Huraira (Allah be pleased with him)
Abu Huraira (Allah be pleased with him) reported: Two types of terrorisations 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.