That day Wukong and the rest were merry and glad, but out before the Three-Star Immortal Cave he kept watching the sky, impatient — evening could not come soon enough.

當日 is that same day, with 當 as dāng, "at, on," not dàng, appropriate or to pawn. 喜喜歡歡 is doubled for merriment. Then the lovely detail: he is out there watching the sky, 急不能到晚 — so impatient that the day cannot get to evening fast enough. (急不能 keeps bù.)

When dusk came, he went to bed with the others, but only feigned to close his eyes, steadying his breath and keeping his spirit collected.

假合眼 is to fake closing the eyes, with 假 as jiǎ, false, not jià, a holiday. But watch what he does while pretending to sleep: 定息存神, steadying the breath and holding the spirit collected. That is already the vocabulary of cultivation. He has started practising before anybody has taught him anything.

In the mountains there was no beating of the watches or passing of the time-arrow, and he could not tell the hour; he simply steadied the breath going in and out of his own nostrils.

打更傳箭 names the two ways a settlement marked out the night — a watchman beating a drum on his rounds, and the graduated float-arrow of a water-clock passed from station to station. The mountain has neither, so there is no way to know the hour, and he has to become his own clock, timing the night by the breath through his own nostrils. 更 is gēng, a night-watch; 調 is tiáo, to regulate, not diào, to transfer or to tune. (不知 keeps bù.)

When it came to about the hour of zi, he rose softly, put on his clothes, stealthily opened the front door, slipped away from the others, and went outside. He lifted his head and looked — it was just such a scene as this:

子時 (zǐ shí) is the hour of 子, roughly eleven at night to one in the morning — first of the twelve double-hours and the dead middle of the night, with the third watch falling inside it. 子 here is the cyclical sign in full tone, not the neutral suffix. His estimate, arrived at by counting his own breathing, turns out to be right.

The bright moon, the clear dew cold;

A five-character regulated poem opens the night. Bright moon, cold dew — nothing in the scene but clarity.

to the eight poles, far and utterly free of dust.

八極 (bā jí) are the eight extremities, the farthest edges of space, and 迥 (jiǒng) is far or remote: not a speck of dust to the ends of the world. 塵, dust, carries its Buddhist sense of worldly defilement as well, so the sky is not merely clean but purified — and it is about to be matched by a purified mind.

In the deep trees secluded birds roost;

宿 is sù, to roost or lodge for the night. The same character reads xiǔ for a night counted as a unit of time, and xiù for a lunar mansion.

at the spring's head the water trickles and flows.

溜 is liū, to slide or trickle, and 汾 (fén) is an uncommon character used here for the splash and rush of water.

Flying fireflies scatter their glimmer;

Fireflies scattering their glimmer. 散 is the verb sàn, to scatter, not sǎn.

passing wild geese rank in formation across the clouds.

Geese in formation across the cloud — and 字排 is exactly the image Chinese reaches for, the birds ranked in the shape of a written character. English sees a V; Chinese sees a 人.

Just at the hour of the third watch —

正直 here stands for 正值, "just at" — precisely the third watch. He has hit it by breathing.

the very time to go seeking the true Way.

應該 is yīng gāi, "ought to, the very time to," with 應 as yīng, should — not the yìng, to respond, of 應對 in the opening passage.

See him take the old path to the back gate, where he found the door standing half open, half shut.

你看他, "see him now," is the storyteller leaning in toward the audience. And there it is: the back door standing 半開半掩, half open, half shut (掩 yǎn, to half-close). Confirmation that the riddle was read correctly. The 兒 of 門兒 is the neutral suffix.

Wukong said gladly: "So the old master truly means to pass the Way to me — that is why he has left the door open!"

注意 here means to intend, to mean to — not the modern "pay attention." And 著 is zhe, marking the door as still standing open. Two segments on, the same character turns up again meaning something quite different.

He shuffled forward, slipped in sideways through the door, and went straight to the foot of the Patriarch's couch.

曳步 (yè bù) is to shuffle forward, dragging the feet quietly (曳 yè, to trail). 側身 is to turn sideways to slip through the gap. 進得 takes 得 as the toneless de that shows the action succeeded, "managed to get in." 榻 is tà, a low couch.

He saw the Patriarch curled up asleep, his face to the wall.

And the master is asleep — 踡跼 (quán jú), curled up in a ball, facing the wall. 朝 here is cháo, facing toward, not zhāo, morning, as in 一朝 a few passages back. Now compare 睡著了 with 開著門 two segments ago: the same character 著, but this one is zháo, meaning he'd succeeded in falling asleep, where the door merely stood open.

Wukong dared not disturb him, and knelt before the couch.

He does not wake him. He kneels. (不敢 keeps bù before the third tone of 敢.)

Before long the Patriarch woke, stretched out both legs, and chanted to himself:

覺來 is to wake, with 覺 as jué, to become aware — not jiào, sleep, as in 睡覺. He stretches out his legs and starts talking to himself, apparently unaware that anyone is in the room. (不多 keeps bù.)

Hard, hard, hard! —

Three times 難 (nán), hard, opening the 詞-stanza like a hammer.

the Way is most arcane;

道最玄: the Way at its most arcane, its darkest.

do not take the golden elixir lightly.

金丹 (jīn dān), the golden elixir, is the goal of inner alchemy — and this is the first time the chapter names outright what kind of teaching is actually on offer. 等閑 (děng xián) means lightly, as a trifle. (Written with 閑, as in the opening passage's 閑時; the variant 閒 is equally common.)

Without meeting the right person to pass the marvelous secret,

至人 (zhì rén) is the perfected or realised person — here meaning the one fit to receive the teaching, rather than to give it. 妙訣 is the marvellous secret formula. (不遇 takes bú before the falling tone of 遇.)

one talks in vain till the mouth is weary and the tongue goes dry!

And the sting in it: preach to the unworthy and you talk yourself hoarse for nothing — 口困舌頭乾, the mouth wearies and the tongue goes dry. He is lamenting the absence of a worthy disciple while that disciple kneels at his bedside, listening to every word. 乾 is gān, dry, not qián as in the 乾 hexagram.