妖精來了 Fiends Have Come
他四眾順街行走，那些人更不遜避。豬八戒村愚，把長嘴掬一掬，叫道：「讓路，讓路。」那些人猛擡頭，看見模樣，一個個骨軟筋麻，跌跌蹡蹡，都道：「妖精來了，妖精來了！」他四众顺街行走，那些人更不逊避。猪八戒村愚，把长嘴掬一掬，叫道：「让路，让路。」那些人猛抬头，看见模样，一个个骨软筋麻，跌跌蹡蹡，都道：「妖精来了，妖精来了！」
逐句解 Line by line
The four of them walked on down the street, and the crowd showed no sign of standing aside.
遜避 is to yield and get out of the way — the deference an ordinary person was expected to show a monk on the road. Nobody offers it, which is the first small signal that this town has stopped observing the usual courtesies.
Zhu Bajie, being a coarse and simple soul, thrust out his long snout and bellowed, "Make way! Make way!"
長 is cháng, meaning long — not zhǎng, which is the same character read as grow or elder. That distinction is about to come up three more times in this chapter and it is always settled the same way: when the word is paired against 短, short, it is a measurement. 村愚 is village-stupid, the novel's standing verdict on Bajie — not malicious, just entirely without judgement about when a pig's face is the wrong thing to lead with.
The crowd jerked their heads up, got a look at him, and every last one of them went soft in the bone and numb in the sinew, staggering and tripping over each other and crying, "Fiends! Fiends have come!"
骨軟筋麻 — bones soft, sinews numb — is exactly what English means by going weak at the knees, and Chinese still reaches for it. 蹡 is qiàng here, the staggering word, rather than the qiāng that describes a stately measured walk. The character carries both, and the company it keeps decides which: these people have just gone numb in the legs.
This is the oldest joke in the book and it never stops working. Bajie tries to help, and the way he helps is by shoving a pig's snout at a crowd of strangers and shouting.
The reaction is worth reading closely, though, because it is not simply comic. These people scream that fiends have come — and the reader knows something they do not, which is that this town's troubles genuinely were sent from above. They are wrong about the four travellers and right about the general principle. Something supernatural has been done to Fengxian. It just is not standing in the market square with a rake.
There is a structural joke buried here too. The pilgrims are mistaken for the disaster at the exact moment they arrive to end it.