不解其意 He Cannot Make Out The Meaning
行者聽了，暗喜道：「妖精也有存心好的。似他後邊這兩句話，說『天理難容』，卻不是個好的？但只說金聖皇后一向無緣，未得沾身，此話卻不解其意。等我問他一問。」行者听了，暗喜道：「妖精也有存心好的。似他后边这两句话，说『天理难容』，却不是个好的？但只说金圣皇后一向无缘，未得沾身，此话却不解其意。等我问他一问。」
逐句解 Line by line
Pilgrim listened, and said to himself with quiet pleasure: "So even fiends may keep a good heart in them."
暗喜 is pleasure kept to oneself, which it has to be — he is sitting on the man's despatch bag at the time. 存心 is the heart a person keeps, the settled disposition rather than a passing mood: what the courier has is not a good impulse but a good character.
"Take those last two sentences of his, where he says Heaven's principle will never allow it — is that not a good one?"
The single quotation marks belong to the edition, setting the courier's own phrase off inside Wukong's sentence. 難 is nán, hard to, exactly as it was when the courier said it a moment ago.
"Only what he said about the Golden Sage Empress — no luck all this while, and never a hand laid on her — that I cannot make out the sense of. Let me put him a question."
解 is jiě, to untie, and so to work out — the same character that unties a knot unties a meaning. The tail runs six characters and carries no he-said of its own, so it goes in with the sentence before it. The same 等我 frame closed the previous scene.
Wukong's reaction is a compliment, and it is paid to nobody. A fiend has said something true about Heaven, and he notes the fact with something close to approval — even fiends may keep a good heart in them — which is a generous reading of a man who has just laid out a plan to sack a city.
But what he actually takes away is the puzzle. Out of everything the courier said — six dead women, a war tomorrow, a kingdom to be taken — the sentence that stops him is the one nobody was meant to notice: three years, and never once able to touch her. The whole plot turns on that clause, and he is the only listener who hears it as a question rather than as background.