理上難行 A Thing Hard to Do in Principle
三藏道：「陛下，你此來是請我徒弟與你去除卻那妖怪麼？」那人道：「正是，正是。」三藏道：「我徒弟幹別的事不濟，但說降妖捉怪，正合他宜。陛下啊，雖是著他拿怪，但恐理上難行。」那人道：「怎麼難行？」三藏道：「那怪既神通廣大，變得與你相同；滿朝文武，一個個言和心順；三宮妃嬪，一個個意合情投。我徒弟縱有手段，決不敢輕動干戈。倘被多官拿住，說我們欺邦滅國，問一款大逆之罪，困陷城中，卻不是畫虎刻鵠也？」那人道：「我朝中還有人哩。」三藏道：「陛下，你此来是请我徒弟与你去除却那妖怪么？」那人道：「正是，正是。」三藏道：「我徒弟干别的事不济，但说降妖捉怪，正合他宜。陛下啊，虽是着他拿怪，但恐理上难行。」那人道：「怎么难行？」三藏道：「那怪既神通广大，变得与你相同；满朝文武，一个个言和心顺；三宫妃嫔，一个个意合情投。我徒弟纵有手段，决不敢轻动干戈。倘被多官拿住，说我们欺邦灭国，问一款大逆之罪，困陷城中，却不是画虎刻鹄也？」那人道：「我朝中还有人哩。」
逐句解 Line by line
Tripitaka said, “Your Majesty, have you come to ask my disciple to go and rid you of that fiend?”
Tripitaka checks what is actually being asked of him before he agrees to anything. 除卻 is to be rid of; 那 is the pointing nà.
The man said, “Just so, just so.”
正是 repeated — "just so, just so." The doubling is eager, and it will be echoed later by Tripitaka himself.
Tripitaka said, “My disciple is of little use at other tasks, but at subduing fiends and catching monsters he is exactly suited.
The most backhanded compliment in the book: my disciple is no use for anything else, but for catching monsters he is perfect. 正合他宜 is "fits him exactly." 降 is xiáng, to subdue.
Yet, Your Majesty, though I might set him to seize the fiend, I fear that in principle it cannot well be done.”
The objection is not moral but jurisdictional — 理上難行, hard to carry out "in principle," meaning within the law. 著他拿怪 has 著 as zhuó, setting someone to a task.
The man said, “Why can it not be done?”
The king cannot see the difficulty, which is the point: he is thinking about a monster, and the monk is thinking about a court. 那 is the pointing nà.
Tripitaka said, “Since that fiend has powers so vast that he has transformed into your very likeness;
The argument opens. Note the shape of it — three parallel clauses building the case before the conclusion lands. 變得 takes the linking de; 相同 is "the same as."
the whole court, civil and military, is with him to a man, in word agreeing and in heart compliant;
Second clause: the whole civil and military court is with him. 言和心順 — agreeing in word and compliant in heart — is the language of a body politic that has been won over, not coerced. 滿朝 has 朝 as cháo; 一個個 takes 一 as yí before a falling tone.
the consorts of the three palaces, every one, are of one mind and one accord with him.
Third clause: so are the consorts. 意合情投 is joined minds and matched feeling — the same phrase one would use of a happy marriage, which is precisely the difficulty.
Though my disciple has his arts, he would never dare lightly to raise shield and spear.
干戈 gān gē is "shield and spear," the old word for armed force. Even Wukong, the argument runs, would not start a war on this evidence.
Were he seized by the throng of officials, charged with cheating the realm and destroying the state, arraigned on a count of high treason, and trapped within the city — would that not be to paint a tiger and carve a swan?”
And the conclusion, which is a legal one: strike at a king everyone accepts and you are not a rescuer, you are a traitor. 大逆 is high treason, the gravest charge in the code. The idiom that closes it is beautifully chosen — 畫虎刻鵠 huà hǔ kè hú, "to paint a tiger and carve a swan," compressed from two old warnings: paint a tiger badly and you get a dog (畫虎不成反類犬), carve a swan badly and you still get a duck (刻鵠不成尚類鶩). Both are about copies that fail — and Tripitaka is deploying them in a chapter about a copy that did not.
The man said, “There is yet someone within my court.”
The reply is quiet and it changes everything. 我朝中還有人哩 — "there is still somebody in my court." 朝 is cháo, 中 the locative zhōng, and 哩 the light closing flourish that makes it sound almost offhand.
Tripitaka answers the plea with law rather than pity, and his reasoning is shrewd. Because the impostor holds court and harem to a man, any attack on the seeming king is treason, and the pilgrims would be the ones arraigned and trapped inside the walls. It is an accurate reading of an impossible position.
The idiom he reaches for is pointed: painting a tiger and carving a swan, both proverbs about botched imitations, in a chapter whose whole crisis is an imitation nobody can fault. Tripitaka fears their own intervention will be the clumsy copy that gives them away. Then the king's reply — there is still somebody in my court — turns the entire design toward the prince, and the plot has its hinge.