“My third disciple's surname is Sha, his religious name Wujing, and your servant also calls him Sha the Monk.”

沙和尚 — Sha the Monk, and it is the plainest name of the three. Monkey is the Pilgrim; Pigsy has a nickname out of a fast-day rule; Sha Monk is simply called a monk. 悟淨, Awakened to Purity, completing the set: Emptiness, Ability, Purity. The Tang monk's three disciples are named for three things he needed.

“By origin he was a monster in the Flowing Sands River, and he too was urged to good by the Bodhisattva and took up the discipline of a monk.”

Shorter again. No mountain, no cave, no country — 流沙河作怪者, one who played the monster in the Flowing Sands River, and that is the whole account of his origins. 秉教沙門 — took up the teaching, entered the monastic gate. The last two characters are a transcription of the Sanskrit for a renunciant, and they happen to begin with the same character as his surname. The three references get shorter each time, and Sha Monk's is the shortest. That is the pattern of his whole existence in the book.

“And that horse is not the one Your Majesty bestowed.”

He volunteers it. Nobody has asked about the horse. Having finished the three men he adds, unprompted, that the animal is not the one he was given. 主公, Your Majesty — literally my lord. The Tang monk has just confessed to losing an imperial gift, and the confession is the fourth thing in a list of three.

Taizong said, “The coat is the same colour — how is it not?”

毛片相同 — the markings match. The emperor has been looking at the horse. And that is the detail that gives the scene its warmth. He gave a horse away fourteen years ago and he still remembers what it looked like well enough to contradict a buddha about it.