وَعَنْ أَبِي هُرَيْرَةَ رضى الله عنه
قَالَ: «نَهَى رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنْ بَيْعِ اَلْحَصَاةِ، وَعَنْ بَيْعِ اَلْغَرَرِ»
The Messenger of Allah (sallallahu alayhi wa sallam) forbade a transaction determined by throwing stones, and the transaction which involves some uncertainty (or cheating).