馬兜鈴 A Drug Called Horse Bell
國王問道：「神僧說藥裡有馬，是甚麼馬？」行者接過口來道：「我這兄弟是這般口敞，他有個經驗的好方兒，他就要說與人。陛下早間吃藥，內有馬兜鈴。」国王问道：「神僧说药里有马，是甚么马？」行者接过口来道：「我这兄弟是这般口敞，他有个经验的好方儿，他就要说与人。陛下早间吃药，内有马兜铃。」
逐句解 Line by line
The king asked, "The divine monk says there was horse in the medicine. What sort of horse?"
A perfectly reasonable question, and exactly the one that must not be answered. 甚 is shén, the question word.
Pilgrim took up the thread. "This brother of mine is loose-mouthed like that. Let him get hold of a good tried prescription and he must tell it to everybody.
接過口來 is to take the words out of somebody else's mouth — which is precisely what he is doing, and the narrator names the manoeuvre while it happens. 兒 is the light suffix, 的 the light de.
"What Your Majesty took this morning had horse-bell in it."
馬兜鈴 is birthwort, a genuine drug of the pharmacopoeia — and its name begins with the character for horse. The save takes eleven characters, and nothing in it can be checked from where the king is sitting.
The damage is done — the king has heard the word horse, and asks the obvious question. Pilgrim takes the words out of his brother's mouth, and the narrator names the manoeuvre while it is happening.
The cover story is built in two moves. First Eight Rules is recast as a man who cannot keep a good prescription to himself, which explains the outburst and flatters everybody in the room. Then the save: what the king took had horse-bell in it — birthwort, a genuine drug whose name happens to begin with the character for horse.
It is a very good lie because almost none of it is false. There is such a drug; it does begin with that word; and Eight Rules really did have a hand in the medicine. Only the connection between the three is invented.