理上不順 Not Clean in Point of Law
行者道：「我日間與那太子誇口，說我的手段比山還高，比海還深，拿那妖精如探囊取物一般，伸了手去就拿將轉來。卻也睡不著，想起來，有些難哩。」唐僧道：「你說難，便就不拿了罷。」行者道：「拿是還要拿，只是理上不順。」唐僧道：「這猴頭亂說。妖精奪了人君位，怎麼叫做理上不順？」行者道：「你老人家只知念經拜佛，打坐參禪，那曾見那蕭何的律法？行者道：「我日间与那太子夸口，说我的手段比山还高，比海还深，拿那妖精如探囊取物一般，伸了手去就拿将转来。却也睡不着，想起来，有些难哩。」唐僧道：「你说难，便就不拿了罢。」行者道：「拿是还要拿，只是理上不顺。」唐僧道：「这猴头乱说。妖精夺了人君位，怎么叫做理上不顺？」行者道：「你老人家只知念经拜佛，打坐参禅，那曾见那萧何的律法？
逐句解 Line by line
The Pilgrim said: 'By day I boasted to that prince, saying my powers were higher than the mountains and deeper than the seas, and that seizing this demon would be like taking a thing from a bag — I'd reach in my hand and pluck him right out.'
He is not worried about the fight; he is embarrassed about the boast. 誇口 is to brag. 探囊取物 — 'to take a thing out of a bag' — is still the everyday Chinese phrase for something effortlessly easy, the way English says 'like taking candy from a baby.' 拿將轉來: grab him and haul him back (將 = jiāng). 那, twice, = nà; 太子: 子 = zǐ; 還, twice, = hái.
'But now I cannot sleep, for thinking it over, there is some difficulty in it.'
睡不著: cannot get to sleep, 著 read zháo, which sets 不 at bù. 有些難: there is a difficulty in it (難 = nán).
The Tang Monk said: 'If you say it is hard, then just do not seize him, and let it be.'
Tripitaka's solution is beautifully simple: if it is hard, don't. 便就不拿了罷 — 'then just don't seize him, and be done' (罷 = ba).
The Pilgrim said: 'Seize him I still mean to; only the thing is not clean in point of law.'
And here is the surprise. 理上不順 means the case will not run smoothly in point of principle — the seizure would not stand up. The Monkey King, of all creatures, has been lying awake worrying about procedure. 還 = hái.
The Tang Monk said: 'This monkey-head is talking nonsense.'
猴頭, 'monkey-head,' is Tripitaka's habitual name for his disciple, insult and endearment in the same breath. 亂說: talking wildly.
'A demon has seized a sovereign's throne — how can you call that "not clean in point of law"?'
A demon has stolen a throne. Where exactly is the legal difficulty? It is the straight man's line, and it is a fair question.
The Pilgrim said: 'You, sir, know only how to chant sutras and worship the Buddha, to sit in meditation and practice Chan — when did you ever look into the statutes of Xiao He?'
The retort is a good one. You know sutras, says Wukong; you have never read a statute. 念經拜佛，打坐參禪 — chanting scriptures and bowing to the Buddha, sitting in meditation and working at Chan — is a four-part portrait of the monk's whole day (參 = cān; 佛 = fó). 蕭何, Xiao He, was the Han statesman who codified the empire's law, so invoking him is like saying 'you have never opened a law book in your life.' Note the two readings of 那 in one sentence: 那曾見 is the questioning nǎ, 'when did you ever?', while 那蕭何 is the pointing nà, 'that Xiao He.'
Wukong's midnight worry is a delightfully unexpected one. He has no doubt at all that he can beat the demon — he has already boasted it would be like taking a thing out of a bag — but he doubts he can prosecute him. The Monkey King, so often simply a weapon with opinions, here turns out to have a lawyer's caution: the seizure would be 理上不順, not clean in point of law.
Tripitaka plays the straight man to perfection. If it is hard, don't do it; and in any case a demon on a stolen throne is plainly a criminal, so where is the difficulty? His common sense sets off his disciple's cleverness, and the mismatch between the meditating monk and the scheming ape is what drives the scene.
Wukong's retort — that his master knows sutras but not the statutes of Xiao He — reaches for the great Han codifier of law as the emblem of due process, and names the passage's real subject: the gap between knowing something is true and being able to prove it. The chapter's concern with sorting false from true has taken a courtroom turn, and it points straight at what Wukong will need next, which is a body.