我且解了鎖 Let Me Undo the Lock
我日間與此怪鬥至天晚方回，與師弟輩細道此情，卻就不曾睡，同他兩個來此。我恐夜深不便交戰，又不知師父下落，所以變化進來，打聽打聽。」唐僧喜道：「八戒、沙僧如今在外邊哩？」行者道：「在外邊。方才老孫看時，妖精都睡著。我且解了鎖，搠開門，帶你出去罷。」唐僧點頭稱謝。行者使個解鎖法，用手一抹，那鎖早自開了。我日间与此怪斗至天晚方回，与师弟辈细道此情，却就不曾睡，同他两个来此。我恐夜深不便交战，又不知师父下落，所以变化进来，打听打听。」唐僧喜道：「八戒、沙僧如今在外边哩？」行者道：「在外边。方才老孙看时，妖精都睡着。我且解了锁，搠开门，带你出去罢。」唐僧点头称谢。行者使个解锁法，用手一抹，那锁早自开了。
逐句解 Line by line
"I fought this fiend all day until nightfall and then went back, and told my brothers the whole of it in detail; and then, without sleeping at all, I came here with the two of them.
The timeline, compressed. He has fought a full day, briefed his team and come straight back out — 卻就不曾睡, and simply did not sleep. The novel does not usually bother telling you Pilgrim is tired, which is why the line is here.
I was afraid a battle at dead of night would go badly, and I did not know where you were, so I changed shape and came in to have a listen."
Two reasons, both good, and the second is the real one. 打聽打聽 doubles the verb to soften it — not "investigate" but "have a bit of a listen", the way you would say "have a look" in English. Doubling a verb like this is one of the friendliest things vernacular Chinese does.
The Tang Monk said gladly, "And are Eight Rules and Sha Monk outside now?"
The first question he has asked about anybody else, and it comes eight lines into the reunion.
Pilgrim said, "They are outside.
Three characters of answer. Pilgrim is already thinking about the lock.
I had a look just now — the fiends are all asleep.
睡著 here is the achieved zháo: not sleeping but fallen asleep, the state arrived at. It is the difference between "he is sleeping" and "he has dropped off", and the whole plan depends on which one it is.
Let me undo the lock and force the door, and I will take you out."
The plan, in thirteen characters, and it ends on 罷 — an everyday sound at the end of a sentence that softens an order into a suggestion. English does it with "shall we" or a rising tone. Modern Chinese writes the same word with a different character. It is read ba, light and unstressed, and not the heavier bà that means to stop.
The Tang Monk nodded his thanks.
Six characters. He is chained to a pillar and cannot do much else.
Pilgrim worked a lock-opening spell, passed his hand across, and the lock sprang open of itself.
用手一抹 — one wipe of the hand. The whole trick is that easy, and the novel spends four characters on it. 早自開了, already open of its own accord, before he has finished the gesture.
A quiet passage that exists to make the next one loud. Nothing goes wrong in it. Pilgrim explains himself, Tripitaka asks after the others, the fiends are reported asleep, and the lock opens at a touch. Every element of a successful rescue is now in place.
The craft is in the pacing. The novel gives the plan its full eleven characters, has the master nod his thanks, and opens the lock without a struggle — three beats of everything going right, laid down deliberately so that the reader relaxes. In a chapter that has already told you three demons live here, that relaxation is the trap.
Worth noticing what Pilgrim does not do: he does not free his master and then go looking for a fight. He has said plainly that a night battle would go badly and that he came in to listen, not to strike. This is the tactically sound version of the monkey, and it lasts about forty more characters.