2 Samuel 16:13
curses <07043> [cursed.]
dirt <06083 06080> [cast dust. Heb. dusted him with dust.]
It was an ancient custom, in those warm and arid countries, to lay the dust before a person of distinction, by sprinkling the ground with water. Dr. Pococke and the consul were treated with this respect when they entered Cairo. The same custom is alluded to in the well-known fable of Ph‘drus, in which a slave is represented going before Augustus and officiously laying the dust. To throw dust in the air while a person was passing was therefore an act of great disrespect; to do so before a sovereign prince, an indecent outrage. But it is probable that Shimei meant more than disrespect and outrage to this afflicted king. Sir John Chardin informs us, that in the East, in general, those who demand justice against a criminal throw dust upon him, signifying that he ought to be put in the grave: and hence the common imprecation among the Turks and Persians, "Be covered with earth," or, "Earth be upon thy head."
