Why four eye-witnesses? It went back to a famous incident in the Arabian desert during one of the Prophet's early military adventures in 626 or 627, when the new faith was just about establishing itself, reducing small hostile communities one by one. The Prophet's favourite wife, Aisha, then perhaps thirteen, had for some reason been left behind by the caravan one evening. She didn't join it again until the morning, and then in the company of a handsome young soldier. There was an uproar among the Prophet's companions. Ali, the Prophet's cousin, thought that the Prophet should get rid of Aisha. The Prophet - now in his mid-fifties - was distressed for days. But Allah intervened; the Prophet had a revelation that Aisha was innocent; that four witnesses were needed to prove adultery; that people spreading unfounded rumours about adultery deserved eighty lashes.
-Among the Believers, by V. S. Naipaul