【明報專訊】If you have a particular fault or weakness or even an injury don't tell your enemy about it! If you do, your enemy will surely find a way to utilise (利用) it against you! That's the significance (意義) of this old saying. "Thomas hurt his wrist just before the tennis finals, but we didn't learn about it until after he had won the championship (錦標賽). When receiving his trophy, he joked about his injury and said you should never tell your enemy that your foot aches."