The Master, just then reining in to gaze about him at leisure, saw that Wukong and his brothers had only now caught up.

按轡徐觀, holding the reins and looking about at leisure — Tripitaka has recovered his composure faster than his dignity. 轡 (pèi) is the bridle-reins; 方到, had only just arrived.

Wujing said, "Master — you weren't thrown from the horse, were you?"

Sha Monk asks the tactful version of the question. 不曾, did not, keeps 不 as bù before the rising tone of 曾; 跌下馬來 is to come off a horse.

The elder scolded: "That wretch of an ape, Wukong — he spooked the horse! It was lucky I could still keep my seat."

長老 is the elder — 長 read zhǎng, senior, not cháng, long. 潑猴, unruly ape, is Tripitaka's favourite name for Wukong when annoyed, which is often. 還騎得住 — 還 (hái) still, with the light de, means managed to stay on. 早是 is luckily, as it turned out.

Pilgrim, with an ingratiating smile, said, "Don't scold me, Master — it was all Zhu Bajie, saying the horse went too slow, so I had him quicken his pace."

陪笑 is the placating smile of someone shifting the blame. 馬行遲 takes 行 as the verb xíng, the horse goes slowly. Then 故此著他快些: 著 is zhuó, the verb meaning to have or make somebody do something — the first time in this chapter it carries that sense, and it will return when the widow starts assigning husbands. 都 is dōu, entirely — the whole thing was Bajie's fault, obviously.

The blockhead, from chasing the horse, had hurried a touch too hard; wheezing and puffing, he grumbled and muttered under his breath: "That's torn it, that's torn it — look, my belly hangs slack and my girdle's come loose."

獃子 (dāi zi), the dolt, is what the narrator calls Bajie when he is not calling him worse. 走急了些兒, hurried a bit too hard; 唧唧噥噥 is the sound of muttering under the breath; 罷了 here is that's done it, that's finished. The clipped 見自肚, 別腰鬆 is a breathless, garbled complaint about a sagging paunch and a belt gone loose — how exactly to parse it is not certain, and probably was not meant to be.

"The load is heavy, I can't shoulder it up, and now you've set me racing back and forth after the horse besides!"

擔子 (dàn zi) is the load, with 擔 as the noun dàn against the verb dān, to carry. 沉重 takes zhòng, heavy; 挑不上來, cannot get it up onto the shoulder, with 不 as bú before 上; 奔奔波波 is being run ragged back and forth.

The elder said, "Disciples — just look, over yonder there's a farmstead. We might well go and beg a night's lodging there."

那壁廂 (nà bì xiāng) is over that way, yonder. 一座莊院 is a manor or farmstead; 借宿 is to beg a night's lodging; 卻好 is how convenient, as it happens. It is very convenient indeed.

Pilgrim, hearing this, quickly lifted his head and looked: sure enough, high in the air auspicious clouds hung and gathered, propitious vapors veiled the sky. He knew at once it must be a conjuration of buddhas and immortals; yet, not daring to divulge the secret of Heaven, he only said, "Good, good, good — let's go and lodge there."

Wukong looks up and sees what nobody else does. 慶雲 (qìng yún) and 瑞靄 (ruì ǎi), auspicious cloud and propitious haze, are the standard tell that a divine being is nearby. 佛仙點化 — 佛 is fó — means a conjuring-up by buddhas and immortals. 半空中 takes 中 as zhōng. And 泄漏天機 is to leak the secret workings of Heaven, which he decides not to do. That decision is the hinge the whole chapter turns on.