Hakīm ibn Hizām is the principal narrator of a hadith that has become very important in the development of contract law in Muslim nations. He is also known as one of the few to have been born within the Kaaba, the holiest site in Islam. His father was Hizam Ibn Khuwaylid. Hizam was a merchant, who asked the prophet Muhammed whether it was permissible for him to sell to a customer goods that he doesn't yet possess (short selling, options or futures contracts in Western parlance). Muhammed forbade that.