Sales in which a Price is paid for Goods to be Delivered Later (As-Salam)

Bukhari :: Book 3 :: Volume 35 :: Hadith 457

Narrated 'Abdullah:

The people used to sell camels on the basis of Habal-al-Habala. The Prophet forbade such sale. Nafi' explained Habalal-Habala by saying. "The camel is to be delivered to the buyer after the she-camel gives birth."