Tripitaka, seeing how clear the water was and being thirsty just then, bade Eight Rules: "Fetch the almsbowl and scoop me up some water to drink."

著 is zhuó again, the reading it takes when it sends somebody off to do a job. The whole catastrophe turns on three characters — 那水清, the water was clear. Clarity is the only evidence Tripitaka consults, and it is exactly the evidence a dangerous river is under no obligation to withhold.

The idiot said, "I was just wanting a drop myself."

哩 closes the sentence and is read li, unstressed. 些兒 takes the little suffix er — just a drop. Bajie's eagerness here is what will make his case the worse of the two.

He took the almsbowl at once, scooped up a bowlful, and handed it to his master.

Three verbs, no comment. The pace changes sharply at this point: the leisurely descriptions are finished and the disaster is carried out in short clauses.

His master drank something less than half and left the greater part; the idiot took it from him and drained it at a draught, then helped Tripitaka to his saddle.

乾 is gān, dry — 飲乾 is to drink a thing dry — and not qián, the reading it takes as the name of a trigram. Watch the arithmetic. The master drinks rather less than half and the pig drains the rest at one pull, and their symptoms will be shared out in exactly that proportion.

Master and disciples found the road and travelled west; not half an hour later the elder groaned from horseback, "My belly aches."

不上半個時辰 is less than half a 時辰, and a 時辰 is a double hour — under an hour by our reckoning. The onset is quick enough to be unmistakable, which spares the story any scene of diagnosis.

Eight Rules said from behind, "I have some belly-ache too."

隨後 keeps him a pace behind his master, and that is where he stays for the whole sequence: always second to complain, always worse off.

Sha Monk said, "It will be from drinking cold water."

想是 offers the reasonable explanation, and it is wrong. Sha Monk's job in this novel is often to supply the sensible reading that the situation has already outrun.

Before he had finished, the master cried out, "It hurts badly!"

疼的緊 — the woodblock prints 的 where a modern text would put 得 to link the verb to how badly it is happening. The printed spelling is kept, and it happens to be read the same way, de. Hold that thought: the very next line prints the other one.

Eight Rules said too, "It hurts badly!"

疼得緊 — the same phrase in the same breath, spelled with 得 this time. The two spellings stand seven characters apart, and together they are the clearest evidence in the chapter that the block-printer treated 的 and 得 as one word.

The two of them could not endure the pain, and little by little their bellies grew large.

難禁 takes 禁 as jīn, to bear or endure, not jìn, to forbid. 漸漸…大了 delivers the revelation without naming it, and lets the reader arrive well before the characters do. 肚 is dù, the belly — the same character reads dǔ for tripe, which is not what is meant.

Feeling with their hands, they seemed to find clots of blood and lumps of flesh stirring ceaselessly, thump and thump.

骨突骨突 imitates something shifting about inside, and sound-words of this kind keep their ordinary readings. 似有 hedges the perception — they seemed to find — which is a good deal more unsettling than certainty would have been.

Tripitaka was in real distress when he suddenly saw, beside the road, a village cottage with two straw bundles hoisted on a pole at the top of a tree.

挑 is tiǎo here, to prop or hoist something on a pole, and not the tiāo of carrying a shoulder-load a few lines back. Two 草把 raised on a pole above a roof is the standard sign of a house that sells drink — the Ming equivalent of a pub sign — which is why Wukong reads it correctly in the next line.

Pilgrim said, "Master, good — that place yonder is a house that sells wine.

好了 registers relief, not approval. Wukong reads the straw sign at a distance, one of the small practical competences the story hands him again and again.

Let us go and beg a little hot broth of them for you, and ask at the same time whether there is any apothecary, and get a dose to treat your belly-ache."

化 is huà, to beg alms — the same verb used of the rice at the chapter's opening. 討貼藥 asks for a single made-up dose, the way one might ask a chemist for a sachet. The plan is entirely reasonable and entirely useless.