一軸畫兒 A Picture Nobody Could Explain
行者一翅飛起，徑又飛至刺史住宅裡面，低頭觀看，那房內裡已有燈光，見刺史已起來了。他就飛進中堂看時，只見中間後壁掛著一軸畫兒，是一個官兒騎著一匹點子馬，有幾個從人打著一把青傘，搴著一張校床，更不識是甚麼故事。行者就丁在中間。行者一翅飞起，径又飞至刺史住宅里面，低头观看，那房内里已有灯光，见刺史已起来了。他就飞进中堂看时，只见中间后壁挂着一轴画儿，是一个官儿骑着一匹点子马，有几个从人打着一把青伞，搴着一张校床，更不识是甚么故事。行者就丁在中间。
逐句解 Line by line
Monkey went up on a wing and flew straight on to the prefect's residence. Looking down, he saw there was already lamplight in the rooms, and the prefect up and about.
一翅飛起 — went up on a wing. Four characters for the whole journey. He has been out of the prison for one night and this is his third house. The prefect is already awake before dawn, which the book mentions without comment. He has a torture session scheduled for the morning and a senior official from the capital to attend to, and he is up early.
He flew into the main hall to look, and saw hanging on the rear wall in the middle a scroll painting: an official riding a dappled horse, with several attendants holding up a green umbrella and carrying a folding camp chair. There was no telling what story it was.
Four verbs in a row and each with the light character after it — 掛著, 騎著, 打著, 搴著. Nothing in this sentence is happening. It is a description of a painting, and the construction that normally means going on here means shown as doing. 校床 — a folding camp chair. The word is written with a character that is a variant, or a slip, for the one normally used: the object is the portable folding seat, sometimes a litter, that travelled with an official's retinue. The character keeps its own reading here and the explanation is carried in this note. It appears once in the whole novel, and the standard spelling appears not at all. 更不識是甚麼故事 — there was no telling what story it was. The first character of that phrase means still and is the one place in this chapter where it is not the night watch — the chapter's other five uses are all the watch, and the reading comes out right here without help.
Monkey perched himself in the middle of it.
丁在中間 — perched in the middle. The verb is written with a bare character where the book normally uses the one with the metal element, meaning to fix or nail something in place. THIS CHAPTER USES BOTH: five hundred and twelve characters ago Monkey perched on the head of Kou Hong's coffin, and the book spelled it the other way. Same word, same construction, two spellings — and this time both come out with the same reading unaided. And note where he settles: in the middle of the painting. He is about to impersonate the man in it.
Monkey works out the whole plan from one look at a wall. He flies in, sees a portrait of an official on horseback that he cannot identify, and perches in the middle of it. He has no idea who the man is. He will find out in a moment, because the prefect is about to tell him.
The painting is described in four clauses that all use the construction for something going on — the horse being ridden, the umbrella being held, the chair being carried — and none of it is going on at all. It is paint. That is a genuinely tricky thing for a reader to catch, and the book gives no signal beyond hanging the whole scene on a wall.
The details are all rank markers. A green umbrella and a folding chair carried by attendants are what an official of standing had on the road. Whoever this is was somebody, which is why his portrait is on the rear wall of the main hall — and why Monkey, who cannot read the situation yet, has picked exactly the right place to sit.