The fine Great Sage plucked a hair, blew on it a breath of immortal air, and cried, “Change!”

The standard opening move of every Wukong scheme: pull a hair, breathe on it, shout 變. 仙氣 is immortal breath; 拔了一根 keeps 一 as yì before a level tone.

It became a box of red-gold lacquer, and setting the white-jade tablet inside it, he said, “Master, take this thing and cradle it in your hands; when day breaks, put on the brocade cassock, go and sit in the main hall to chant the sutras, and let me go take a look at that city of his.

The hair becomes a red-and-gold lacquer casket, and the tablet goes inside it. Then the staging instructions: put on the brocade cassock, sit in the main hall, chant, and look like an ordinary travelling monk. 匣兒 ends in the light er; 坐著 has 著 as zhe, holding the action open; 將此物 has 將 as jiāng; 那城池 takes the pointing nà. (The sealed note reads 盛著 as chéng zhe, the verb for holding something in a vessel, where the ruby gives shèng.)

If he is truly a fiend, then to strike him dead would be to set up a merit here;

And here, unexpectedly, a note of caution. If he really is a fiend, killing him earns merit; 功績 is a meritorious deed, the kind that goes on a record. 端的 is "truly, genuinely"; 此間 is "here."

but if he is not, do not go courting disaster.”

But if not, leave it alone. 撞禍 is to run headlong into disaster. Wukong insisting on verification before violence is rare enough to be worth marking. 不是 takes 不 as bú before a falling tone.

Tripitaka said, “Just so, just so.”

正是 twice over — the same eager doubling the ghost used when Tripitaka first guessed what he wanted. Master and ghost now sound alike.