Tu Mu says that 依 here = 近. The idea is, not to linger among barren uplands, but to keep close to supplies of water and grass. Capt. Calthrop translates “camp in valleys,” heedless of the very next sentence. Cf. Wu Tzŭ, ch. 3: 無當天竈 “Abide not in natural ovens,” _i.e._ 大谷之口 “the openings of large valleys.” Chang Yü tells the following anecdote: “武都羗 Wu-tu Ch‘iang was a robber captain in the time of the Later Han, and 馬援 Ma Yüan was sent to exterminate his gang. Ch‘iang having found a refuge in the hills, Ma Yüan made no attempt to force a battle, but seized all the favourable positions commanding supplies of water and forage. Ch‘iang was soon in such a desperate plight for want of provisions that he was forced to make a total surrender. He did not know the advantage of keeping in the neighbourhood of valleys.” 2. 視生處高戰隆無登此處山之軍也 Camp in high places, Not on high hills, but on knolls or hillocks elevated above the surrounding country. facing the sun. 視生 = 面陽. Tu Mu takes this to mean “facing south,” and Ch‘ên Hao “facing east.” Cf. _infra_, §§ 11, 13. Do not climb heights in order to fight. 隆 is here simply equivalent to 高. The _T‘ung Tien_ and _Yü Lan_ read 降. So much for mountain warfare. After 山, the _T‘ung Tien_ and _Yü Lan_ insert 谷. 3. 絶水必遠水 After crossing a river, you should get far away from it. “In order to tempt the enemy to cross after you,” according to Ts‘ao Kung, and also, says Chang Yü, “in order not to be impeded in your evolutions.” The _T‘ung Tien_ reads 敵若絶水 “If _the enemy_ crosses a river,” etc. But in view of the next sentence, this is almost certainly an interpolation. 4. 客絶水而來勿迎之於水內令半濟而擊之利 When an invading force crosses a river in its onward march, do not advance to meet it in mid-stream. It will be best to let half the army get across, and then deliver your attack.