Legend has it that in the eleventh century, when the very eccentric and possibly demented Caliph El Hakim needed some money, he wrote a letter to the governor of Jerusalem asking that a tax be levied. The governor wrote back that this was impossible--most of the people were poor, many of them monks who lived in caves in Wad er-Rabâbeh. El Hakim asked his scribe to write a letter with the command "Count the men." Whether the scribe made a mistake or whether the letter was intercepted, no one really knows. But by the time the letter arrived in Jerusalem it read "Castrate the men." In Arabic, the difference between the two verbs hasaa and khasaa is a single dot.
(from The Dot Matrix, by Laila Lalami in The Nation)