摩訶止觀 7.197

7.197

○若能如上勤而行之，於一生中必不空過。雖聞不用，如黑蚖懷珠，何益於長蛇者乎？今以三譬譬於得失。匹夫隻勇，修治一刀一箭，破一寇兩寇，獲賜一金一銀，祿潤一妻一子。如此之人但利器械，負戟前驅以命博貨，何用廣知兵法耶？若欲為國，麴糵、舟楫、鹽梅、霖雨者，須善文武，計在帷帳，折衝萬里。所學處深，所破亦大；獲賞既重，祿潤甚多。雖知而不用，用而屢北；尚不能濟身，澤豈及人乎？

If one can practice diligently as described above, one will certainly not pass through a single lifetime in vain. Although hearing it, if one does not apply it, it is like a black viper holding a pearl—what benefit does it bring to a long serpent? Now three parables are used to illustrate the gains and losses. A common soldier with singular bravery polishes a single sword and a single arrow, defeats one or two raiders, receives a reward of a piece of gold or silver, and provides livelihood for a single wife and child. Such a man merely sharpens his weapons, carries a halberd at the front, and risks his life to barter for goods; what use would he have for broad knowledge of the art of war? But if one wishes to be the yeast, the boat and oars, the salt and plums, or the torrential rain for a state, one must be skilled in civil and military affairs, plan within the tent, and overcome enemies ten thousand li away. Where one studies is deep, and what one destroys is also great; the rewards received are heavy, and the livelihood provided is vast. Although knowing it, if one does not apply it, or applies it and repeatedly suffers defeat, one cannot even save oneself—how could one's bounty extend to others?