The aside is a fossil of oral performance. A storyteller who has just made a horse bolt at Wukong’s shout anticipates the obvious objection — Bajie was shouting too — and stops to dispose of it before going on. The 世德堂本 prints it as a paragraph of its own, and it reads as one: a complete question-and-answer that could be lifted out without disturbing the narrative on either side.

What the answer supplies is not really an explanation but a joke with a long history behind it. Wukong’s 弼馬溫 appointment in chapter four was the insult that began his rebellion, the title he could not bear to hear; here it is quietly repurposed as a piece of practical animal lore. The novel has been calling him 弼馬溫 in mockery for fifty chapters, and this is the one place where the office turns out to have been good for something.

There is also a real folk belief underneath it. Stabling a monkey to keep horses healthy is attested well before the novel, and the pun that gives Wukong his title — 弼馬溫 for 避馬瘟 — is the belief compressed into three graphs. The aside thus works in both directions: it explains the horse by the myth, and the myth by the horse.