Now it is told that Sanzang, watching for the Pilgrim and finding him slow to return, grew heavy with doubt:

話說 resumes the storyteller's frame after the chapter break. 心甚疑惑: 甚 is the adverb shèn, "very," not the interrogative shén of 甚麼. Sanzang's first movement in the chapter is, as so often, suspicion of his own disciple.

he could not tell whether the Bodhisattva had refused to come, or whether the Pilgrim had found a pretext and run off.

The two 不知 clauses are alternatives, not a doubled negation: "he did not know whether… or whether…" The second alternative — that Wukong has bolted — is the fear that runs under the whole first third of the pilgrimage, and it will resurface in this very chapter when the monk is left alone in a stranger's house.

In the very midst of these wild surmises he saw, high in the air, a bright shimmer of coloured mist,

胡猜亂想, "wild guessing and disordered imagining," is a fixed four-graph phrase of the vernacular novel. 彩霧燦燦 — the reduplicated 燦燦 gives the shimmer its glitter; both 中 here are zhōng.

and the Pilgrim dropped suddenly before the steps and knelt, saying, "Master, the cassock is come back."

忽墜階前: the verb 墜 is a fall, not a landing. The Pilgrim does not alight; he drops. That he then kneels is a courtesy he pays about once a chapter.

Sanzang was overjoyed. Nor was there one among the monks who did not rejoice, crying, "Good! Good! Only today are our lives made whole again."

得全 takes 得 as dé, "to obtain," not the resultative de: the monks' lives are had whole, not merely made so. 方才, "only just now" — the fire of chapter sixteen has been burning under their gratitude for two chapters.

Sanzang received the cassock and said, "Wukong, when you set out this morning you promised to be back by the noon meal. How is it that you return only now, with the sun already west?"

飯罷晌午: after the meal, at midday. 日西方回 is elliptical — "the sun west, only then to return." Sanzang counts hours; it is the closest thing to reproach he permits himself here.

The Pilgrim laid out for him, from beginning to end, the whole business of inviting the Bodhisattva, of the transformations wrought, and of the monster subdued.

備陳, "to set out in full," is the narrator's standard device for skipping a recapitulation the reader has just finished. 降妖: 降 is again xiáng. 一遍 takes the mechanical sandhi yí before the fourth-tone 遍.

When Sanzang had heard him out he set up an incense table, made his obeisance toward the south, and then said,

朝南禮拜: the obeisance is made southward because Potalaka (落伽山) lies in the southern sea. 朝 is cháo, "to face, to turn toward," not zhāo, "morning." The rite is directed at Guanyin, not at the Buddha.

"Disciple, since the Buddha's robe is ours again, make haste to gather up the bundles, and let us be gone."

The colloquial vocative 徒弟啊 and the sentence-final 也 mark this as speech rather than narration. 佛衣 — Buddha-robe — is the cassock under its most exalted name; 佛 is baked as fó globally.