Prayers (Salat)
Bukhari :: Book 1 :: Volume 8 :: Hadith 364
Narrated Abu Huraira:
The Prophet forbade two kinds of sales i.e. Al-Limais and An-Nibadh (the former is a kind of sale in which the deal is completed if the buyer touches a thing, without seeing or checking it properly and the latter is a kind of a sale in which the deal is completed when the seller throws a thing towards the buyer giving him no opportunity to see, touch or check it) and (the Prophet forbade) also Ishtimal-As-Samma' and Al-Ihtiba' in a single garment.