19. Let your plans be dark and impenetrable as night, and when you move, fall like a thunderbolt.
The original text has 震 instead of 霆. Cf. IV. § 7. Tu Yu quotes a saying of T‘ai Kung which has passed into a proverb: 疾雷不及掩耳疾電不及瞑目 “You cannot shut your ears to the thunder or your eyes to the lightning — so rapid are they.” Likewise, an attack should be made so quickly that it cannot be parried.
20. When you plunder a countryside, let the spoil be divided amongst your men;
The reading of Tu Yu, Chia Lin, and apparently Ts‘ao Kung, 指向分衆, which is explained as referring to the subdivision of the army, mentioned in V. §§ 1, 2, by means of banners and flags, serving to point out (指) to each man the way he should go (向) But this is very forced, and the ellipsis is too great, even for Sun Tzŭ. Luckily, the T‘ung Tien and Yü Lan have the variant 嚮, which not only suggests the true reading 鄉, but affords some clue to the way in which the corruption arose. Some early commentator having inserted 鄉 as the sound of 鄉, the two may afterwards have been read as one character; and this being interchangeable with 向 鄉 must finally have disappeared altogether. Meanwhile, 掠 would have been altered to 指 in order to make sense. As regards 分衆, I believe that Ho Shih alone has grasped the real meaning, the other commentators understanding it as “dividing the men into parties” to search for plunder. Sun Tzŭ wishes to lessen the abuses of indiscriminate plundering by insisting that all booty shall be thrown into a common stock, which may afterwards be fairly divided amongst all.
when you capture new territory, cut it up into allotments for the benefit of the soldiery.
That this is the meaning, may be gathered from Tu Mu’s note: 開土拓境則分割與有功者. The 三略 gives the same advice: 𫉬地裂之. 廓 means “to enlarge” or “extend” — at the expense of the enemy, understood. Cf. Shih Ching, III. 1. vii. 1: 憎其式廓 “hating all the great States.” Ch‘ên Hao also says 屯兵種蒔 “quarter your soldiers on the land, and let them sow and plant