蟹介士 The Crab Gentleman at Arms
座上眾精聞言，都拱身對老龍作禮道：「蟹介士初入瑤宮，不知王禮，望尊公饒他去罷。」老龍稱謝了。眾精即教：「放了那廝，且記打，外面伺候。」大聖應了一聲，往外逃命，徑至牌樓之下。座上众精闻言，都拱身对老龙作礼道：「蟹介士初入瑶宫，不知王礼，望尊公饶他去罢。」老龙称谢了。众精即教：「放了那厮，且记打，外面伺候。」大圣应了一声，往外逃命，径至牌楼之下。
逐句解 Line by line
The spirits at the table, hearing this, all bowed with folded hands to the old dragon and said, "The Crab Gentleman-at-Arms has but newly entered the jasper palace and does not know the royal courtesies. We beg your honour to let him go."
都 is dōu, all of them. Watch what has just happened: the company picks up the title the prisoner invented for himself one passage ago and uses it as though it were on a register. 蟹介士 is now his name at court. 罷 is the imperative ba.
The old dragon expressed his thanks.
稱 is chēng. Four characters, and the host has been thanked into a pardon he did not offer.
The spirits then gave order: "Turn the fellow loose, set his beating down on record, and let him wait outside."
教 is jiào, to order. 且記打 is a clerk's formula: the beating is not remitted but written down in the book against him, to be administered another day or never.
The Great Sage answered with a sound, fled outside for his life, and went straight to the foot of the archway.
應 is yìng, to answer, not the yīng of ought. 一 takes yì before the level tone of 聲.
The acquittal is granted on the strength of an invented office. The company petitions on behalf of the Crab Gentleman-at-Arms, a title that existed nowhere until the prisoner coined it in verse a moment ago, and the old dragon accepts both the title and the plea. A rank asserted in a lyric has become a fact of the record inside four lines.
The disposal is beautifully bureaucratic. He is not pardoned; the beating is entered in the book, and he is told to wait outside — which is to say the file stays open and the sentence is deferred rather than cancelled. The heavens and the waters of this novel run on identical paperwork, and we met the same instinct at the opening of the chapter, where a Local Spirit imagined his release as the return of a written decree.
The last clause quietly repositions him. Sent outside to wait, the Great Sage goes to the foot of the archway — which is where the golden-eyed beast is tethered. The court has just parked its prisoner, unsupervised, next to the one object in the palace he has any use for.