變作花腳蚊蟲 A Speckle-Legged Mosquito
他將身一縱，徑到他門首，門尚關著睡覺。行者不叫門，且不驚動妖怪，捻著訣，念個咒語，搖身一變，變做一個花腳蚊蟲，真個小巧。有詩為證。詩曰：他将身一纵，径到他门首，门尚关着睡觉。行者不叫门，且不惊动妖怪，捻着诀，念个咒语，摇身一变，变做一个花脚蚊虫，真个小巧。有诗为证。诗曰：
逐句解 Line by line
He gave his body a leap and came straight to the fiend's gate, and the gate was still shut, for they were sleeping within.
將身一縱: 將 is jiāng, setting up the thing acted on. 關著睡覺 — 著 is zhe, the state held: the gate stays shut all the while they sleep behind it.
The Pilgrim did not call at the door, and would not disturb the fiends. He made the finger-sign, spoke a spell, shook himself, and changed into a speckle-legged mosquito, a very neat small thing.
捻著訣 is to pinch the fingers into the magical sign; 著 is zhe again. 花腳蚊蟲 is a "flower-legged" mosquito, which is to say a speckle-legged one. 真個小巧, "truly neat and small," is said with approval — the narrator admires the workmanship.
There is a poem to prove it. The poem says:
有詩為證。詩曰： is the double announcement, with 為 read wèi. Both clauses stay in the prose segment, by house rule.
A shape too small to trouble with, and a sharp proboscis; / a thin singing voice, and it comes like thunder.
擾擾 is "swarming, bothersome," and 利喙 the keen bill. Notice that the poem never names its subject — that is the whole convention of the riddling description-poem, and the answer is withheld until the last line.
Through orchid chamber and gauze bed-curtain it passes at its ease, / loving best the warm airs of the burning summer.
蘭房紗帳, the orchid chamber and the gauze bed-curtain, are the standard furniture of a lady's bedroom in love poetry, and the mosquito goes through them as though they were not there. In the 維基文庫 text this unit and the next each carry a stray plain space mid-line, removed here.
It fears only the smoke and the beating fan, / and dotes upon the brightness of the lamp.
撲扇: 扇 reads shàn, the fan. The couplet balances two opposed verbs, 怕 and 憐 — the insect fears the thing men use against it and dotes on the thing that draws it in and kills it anyway.
Light, light, and small, small, and far too quick at boring in — / it flew into the fiend's cave.
忒 (tè) is the intensifier again, the same word Bajie used a few passages back. 鑽疾 is "quick at boring through." The last clause drops the riddle and simply says what has happened.
The mosquito-poem is a small tour de force in a genre this novel keeps quoting: the 詠物, the verse on a thing, which describes its subject with complete accuracy and flatly refuses to name it. Every couplet is a pair of opposites — a shape too small to see against a voice like thunder, gauze curtains against summer heat, the feared smoke against the beloved lamp — and only in the final line, as it flies into the cave, does the poem admit whose shape this is.
Notice where the Pilgrim has been put. Two passages ago he could not see at all; now he takes the form of a creature that finds its way in the dark by heat and smell, and goes in through a shut door. The chapter took his eyes away and then, by way of the guardian spirits' ointment, gave them back sharper than before — 比常更有百分光明 — so that he could use them at the size of an insect. This is the last outcome the wind-demon would have chosen.