將計就計 Turning Their Plot Against Them
只見那眾僧們搬柴運草，已圍住禪堂放火哩。行者暗笑道：「果依我師父之言，他要害我們性命，謀我的袈裟，故起這等毒心。我待要拿棍打他啊，可憐又不禁打，一頓棍都打死了，師父又怪我行兇。罷，罷，罷，與他個順手牽羊，將計就計，教他住不成罷！」只见那众僧们搬柴运草，已围住禅堂放火哩。行者暗笑道：「果依我师父之言，他要害我们性命，谋我的袈裟，故起这等毒心。我待要拿棍打他啊，可怜又不禁打，一顿棍都打死了，师父又怪我行凶。罢，罢，罢，与他个顺手牵羊，将计就计，教他住不成罢！」
逐句解 Line by line
And there he saw the monks, hauling firewood and carrying straw, already ringing the meditation hall about, ready to set it burning.
哩 is the vernacular sentence-final particle. The clause is deliberately anticlimactic: he emerges from the rafters expecting robbers and finds his hosts.
The Pilgrim laughed to himself. "It is just as my master said. They mean to have our lives, and to take my cassock; that is why they have raised so venomous a heart.
果依我師父之言 — "it has fallen out just as my master said." He concedes the point, silently, and to himself, in the same breath in which he decides to ignore its moral. Sanzang's counsel was 索之而必應其求: give it back when they ask. Wukong's conclusion is that they must be punished.
"I have a mind to fetch out my cudgel and lay into them — but the pity is they cannot stand a beating, and one blow of the cudgel would kill the lot; and then my master would blame me for cruelty.
The restraint is real and its ground is not mercy: 可憐又不禁打, "the pity is that they cannot take a beating." He spares them because they are too fragile to be worth striking, and because 師父又怪我行兇 — his master would scold. This is the moral condition of the Great Sage at chapter sixteen: he has a golden fillet on his head and no compunction under it.
"Enough, enough, enough. I will let them lead the sheep away by the halter, and turn their own plan against them, and see to it that they do not stay here at all!"
順手牽羊 ("to lead off a sheep as one passes") is the proverb for taking an opportunity that presents itself; 將計就計 ("to meet a stratagem with the stratagem itself"), the thirty-first of the Thirty-Six Stratagems. 教他住不成: to see to it that they cannot go on living here. He is about to protect two men and destroy a monastery, and he says so plainly.
The novel gives Wukong a soliloquy of four sentences, and in them he weighs, decides, and condemns. He could kill them with the cudgel; he will not, partly because they are too soft to be worth killing and chiefly because Sanzang would object. So he chooses fire — not to light it, they have done that, but to feed it, and to let it do what his cudgel is forbidden to do. 將計就計, "meet their stratagem with their own": the phrase is admiring in Chinese, the mark of a tactician, and it names an act that will leave two hundred monks homeless in the ashes by dawn.
The chapter has been, until this moment, a study in the corruption of a religious house. From here it becomes something harder to place. Wukong is entirely right: the monks are murderers, they meant to burn a sleeping man and a horse, and nothing that happens to them is undeserved. He is also, by any reckoning the novel elsewhere endorses, doing a wicked thing — 教他住不成罷, "let them have no house to live in" — and doing it with the same untroubled satisfaction with which Guangmou proposed his fire. The golden fillet was set on this head in chapter fourteen precisely because the head could not be trusted, and this passage is the first demonstration since of what it was for. Guanyin will collect on it, in her own person, before the next chapter is out.