殿上尋童 No Trace in the Hall
行至殿上，香火全無，人蹤俱寂，那裡有明月、清風。眾仙道：「他兩個想是因我們不在，拐了東西走了。」大仙道：「豈有此理！修仙的人，敢有這般壞心的事？想是昨晚忘卻關門，就去睡了，今早還未醒哩。」行至殿上，香火全无，人踪俱寂，那里有明月、清风。众仙道：「他两个想是因我们不在，拐了东西走了。」大仙道：「岂有此理！修仙的人，敢有这般坏心的事？想是昨晚忘却关门，就去睡了，今早还未醒哩。」
逐句解 Line by line
But when he came to the hall, the incense-fires were all out and every trace of men was still—nowhere were Bright Moon and Clear Wind to be found.
The good mood lasts exactly one room. 香火全無, the incense-fires all out — in a working temple somebody tends those from dawn, so a cold censer says at once that nobody has been here. 人蹤俱寂, rén zōng jù jì, every trace of people silent. 那裡有 is nǎ lǐ yǒu, "where are they?" used as a flat "nowhere" — interrogative 那 as nǎ.
The immortals said, "The two of them, we suppose, took advantage of our absence, made off with the goods, and fled."
The company jumps straight to the ugly explanation: the boys have robbed the place and run. 拐了東西走了, guǎi le dōng xi zǒu le, "made off with the things and left."
The Great Immortal said, "What an absurd idea!
豈有此理, qǐ yǒu cǐ lǐ — "how could there be such a principle!" — is one of those phrases that has survived intact into modern speech; it is what you say today when told something outrageous. Word for word it appeals to reason itself: there is no world in which that follows.
"Would men who cultivate immortality dare do so wicked a thing?
修仙的人, xiū xiān de rén, is one who cultivates immortality — a long discipline of practice, so the master's point is that a man who has spent centuries on self-perfection does not steal the silverware. 壞心的事, a deed of ill intent.
"They must have forgotten to lock the gate last night and gone off to sleep, and are not yet awake this morning."
And so he lands on the innocent version: 忘卻關門, they forgot to shut the gate, and slept in. 還未醒 takes 還 as hái, "not yet," rather than the huán of 還丹, the reverted elixir. He is grotesquely close to right — they are indeed still asleep — and completely wrong about why.
The Great Immortal's decency is what makes this passage bite. Presented with an empty hall and two missing attendants, his household reaches for theft and desertion; he refuses to believe it, on the reasonable ground that men who have spent lifetimes cultivating themselves do not run off with the goods.
His alternative — they forgot the gate and overslept — is very nearly the truth, and that near-miss is the joke. The boys are asleep, and the gate was indeed left open. What he cannot imagine is the reason, and his refusal to think badly of them is exactly what stops him from getting there.