一口吹息燈 One Breath Blows Out The Lamp
卻又剔亮了燈，解放沙僧。八戒綑急了，忍不住大聲叫道：「哥哥，我的手腳都綑腫了，倒不來先解放我？」這獃子喊了一聲，卻早驚動老妖。老妖一轂轆爬起來道：「是誰人解放？」那行者聽見，一口吹息燈，也顧不得沙僧等眾，使鐵棒，打破幾重門走了。却又剔亮了灯，解放沙僧。八戒捆急了，忍不住大声叫道：「哥哥，我的手脚都捆肿了，倒不来先解放我？」这呆子喊了一声，却早惊动老妖。老妖一毂辘爬起来道：「是谁人解放？」那行者听见，一口吹息灯，也顾不得沙僧等众，使铁棒，打破几重门走了。
逐句解 Line by line
Then he trimmed the lamp bright again and untied Sha Monk.
He puts the light back up before freeing anyone, which is a burglar's instinct. 解放 here is simply to loose and let go - untying a rope, in the plainest sense.
Eight Rules had been tied up until he was frantic, and could not hold himself back from bawling out: "Brother! My hands and feet are swollen with the ropes - why not come and untie me first?"
Everything that goes wrong next goes wrong here. 綑急了 is to be tied up to the point of desperation, and the novel grants him that much - his hands really are swollen. Then he does the one thing that will undo the rescue, and he does it out of hurt feelings about the order of release.
This idiot let out one shout, and had already startled the old fiend awake.
卻早 - and already - closes the door before the reader has finished reading. There is no interval between the shout and the consequence.
The old fiend came scrambling up in a roll and said: "Who is that untying somebody?"
一轂轆 is a sound-and-motion word for something rolling over - it is the same root as the everyday word for a wheel, and it puts a nine-headed monster on the floor scrabbling to get up. Even here the novel will not let him be dignified.
That Pilgrim heard him, blew out the lamp with one breath, and without so much as a thought for Sha Monk and the others, used his iron cudgel to smash through several sets of doors and was gone.
The decision takes no time at all. 得 is de in 顧不得, the linking reading in the pattern that means cannot manage to see to something - so he did not so much abandon them as find he had no room to attend to them. It is the most defensible possible phrasing for leaving five bound people in a dark room, and the novel supplies it without comment.
The rescue fails in five segments, and it fails because Eight Rules wanted to be untied first. That is the whole mechanism. Pilgrim gets out, flattens the guards, frees Sha Monk, and then a pig with pins and needles shouts about the queue.
The novel is careful to make him sympathetic while he does it. His hands really are swollen; he really has been tied up longest; he has spent the day watching his brother beaten and expecting his own turn on the schedule. None of that stops the shout being the single worst thing anyone does in the chapter.
And then the last line, which is the one to sit with. Pilgrim blows out the lamp and leaves - not fighting, not arguing, not attempting the other four. The phrase used is the polite one, the one that means he could not manage to attend to them, and the book hands it over without a word of judgement in either direction.