再停一時 Wait A While And Improve
你是怎的看我哩？我醜便醜，奈看，再停一時就俊了。」那老者見他說出人話來，只得開言問他：「你是那裡來的？」你是怎的看我哩？我丑便丑，奈看，再停一时就俊了。」那老者见他说出人话来，只得开言问他：「你是那里来的？」
逐句解 Line by line
How do you find me, then?
Seven characters, and 怎的看我 is genuinely asking for the verdict. Bajie has invited the man who has just called him inhuman to go on.
Ugly I may be, but I am worth a look — give it a while and I shall come out handsome."
我醜便醜 is a set concessive shape — ugly, granted, ugly — and it turns up twice within a few lines here, once from the old man and once from Bajie. 奈看 is worth looking at, bearable to the eye. And 再停一時就俊了 is a promise nobody has asked for: wait a bit and I shall improve.
The old man, hearing him talk like a human being after all, had no choice but to speak up and ask, "Where have you come from?"
說出人話來 is the hinge — speech is what gets him readmitted to the species, having just been denied it on the evidence of his face. 只得 is had no choice but, with 得 as dé after an adverb. And the second 那 is nǎ, the interrogative — where from, not that place.
Bajie's tactic is the opposite of his brother's and it works. Pilgrim answered insults by escalating; Bajie answers them by agreeing and asking for more.
The promise to improve with time is pure Bajie. It is not a defence, it is not a joke exactly, and it is certainly not true — but it is disarming, which is the only thing it needs to be.
And the old man gives way, on a precise ground: the creature talks. Having graded the first monk at three parts human on his face, he readmits the second on his speech. The chapter is quietly making a point about what counts as a person.