Ibn al-Musayyib, Hasan, and Ata said: Whether the condition is stated afterwards or beforehand, in every case action will be according to the condition.

Narrated Abu Huraira: Allah's Apostle forbade (1) the meeting of the caravan (of goods) on the way, (2) and that a residing person buys for a bedouin, (3) and that a woman stipulates the divorce of the wife of the would-be husband, (4) and that a man tries to cause the cancellation of a bargain concluded by another. He also forbade An-Najsh (see Hadith 824) and that one withholds the milk in the udder of the animal so that he may deceive people on selling it.