烏金丹 The Black Gold Elixir
多官隨至館中，對行者拜伏於地道：「我王特命臣等拜領妙劑。」行者叫八戒取盒兒，揭開蓋子，遞與多官。多官啟問：「此藥何名？好見王回話。」行者道：「此名烏金丹。」多官随至馆中，对行者拜伏于地道：「我王特命臣等拜领妙剂。」行者叫八戒取盒儿，揭开盖子，递与多官。多官启问：「此药何名？好见王回话。」行者道：「此名乌金丹。」
逐句解 Line by line
The officials came to the hostel accordingly, prostrated themselves on the ground before Pilgrim, and said, "Our king has expressly commanded us to receive the marvellous remedy."
拜伏於地 is full prostration, face to the floor, and 妙劑 is about the most respectful word available for a prescription. Both are being addressed to a box of soot.
Pilgrim told Eight Rules to bring the box, lifted the lid, and handed it over to the officials.
They receive it on their faces; he hands it over without a word of ceremony. The box and its lid take different pet endings inside one clause — the light er of 盒兒, the light zi of 蓋子.
The officials asked respectfully, "What is this medicine called? So that we may report properly to the king."
好見王回話 — so that we can report properly — is a courtier's way of asking the same question twice.
Pilgrim said, "It is called the Black Gold Elixir."
And the name is not a lie. 烏金, black gold, is also an old word for coal.
The officials go down on their faces and ask for the marvellous remedy. Pilgrim has Eight Rules fetch the box, lifts the lid, and hands it over without a word of ceremony. That gap — between how the thing is received and how it is given — is the whole comic structure of the passage.
Then the name, and the name is not a lie. Black Gold Elixir sounds like an alchemist's boast, and black gold is also an old word for coal. Everything in this chapter that sounds like a claim turns out, on inspection, to be a description.