倒換關文 The Travel Rescript Must Be Endorsed
行者道：「卻不是『朱紫國』三字？」三藏道：「朱紫國必是西邦王位，卻要倒換關文。」行者道：「不消講了。」行者道：「却不是『朱紫国』三字？」三藏道：「朱紫国必是西邦王位，却要倒换关文。」行者道：「不消讲了。」
逐句解 Line by line
Pilgrim said, "Are they not the three characters 'Purpuria'?"
朱紫國 — vermilion-and-purple — names the kingdom after the two colours worn by high office. It runs to exactly three characters, which is what the banner was said to carry.
Tripitaka said, "Purpuria must be a kingdom of the western regions, and we shall have to get our travel rescript endorsed."
倒 is dǎo here, the verb: 倒換 is to swap one thing for another. The same character read dào is an adverb meaning 'on the contrary', which is how it turns up elsewhere in the book.
Pilgrim said, "No need to say more."
不消 is everyday speech for 'no need to'. It closes the argument rather than conceding it.
Pilgrim wins by the simple method of reading the banner aloud, and the narrator gives him no line of triumph. Tripitaka does not concede, apologise, or acknowledge that he has just been proved wrong. He moves straight to procedure.
That move is characteristic and it is also practical. The rescript has to be endorsed at every kingdom the pilgrims pass, so what looks like changing the subject is the only business that will get them in one gate and out the other.
Pilgrim's 不消講了 is the last word, and it is faintly rude — not 'you are right' but 'enough said'. He has made his point and declines to make it twice.