["In order to prevent treachery," says Wang Hsi. The general meaning is made clear by Ts’ao Kung’s quotation from the _Ssu-ma Fa:_ "Give instructions only on sighting the enemy; give rewards when you see deserving deeds." Ts’ao Kung’s paraphrase: "The final instructions you give to your army should not correspond with those that have been previously posted up." Chang Yu simplifies this into "your arrangements should not be divulged beforehand." And Chia Lin says: "there should be no fixity in your rules and arrangements." Not only is there danger in letting your plans be known, but war often necessitates the entire reversal of them at the last moment.]