你還老實 Honest As A Whole Regiment
八戒道：「師父，莫怪我說。若論賭變化，使促掐，捉弄人，我們三五個也不如師兄；若論老實，像師兄就擺一隊伍，也不如我。」唐僧道：「正是，正是，你還老實。」八戒道：「师父，莫怪我说。若论赌变化，使促掐，捉弄人，我们三五个也不如师兄；若论老实，像师兄就摆一队伍，也不如我。」唐僧道：「正是，正是，你还老实。」
逐句解 Line by line
Bajie said, "Master, do not take offence at what I say.
莫怪我說 is the standard opener for something the speaker knows will not be welcome. Bajie has been waiting for this.
For gambling on transformations, playing sharp tricks and making fools of people, three or five of us together are no match for my elder brother;
使促掐 is to play a mean trick — to pinch, to work a small cruel angle — and 捉弄人 is to make a fool of somebody. Bajie is listing his brother's gifts, and every item on the list is a vice.
but for plain honesty, you could line my elder brother up in a whole regiment of himself and he would still be no match for me."
擺一隊伍 is the joke: draw the man up in ranks, a whole company of him, and the total honesty still comes to less than mine. It is a quantitative claim about a quality, which is exactly the kind of argument Bajie makes.
The Tang Monk said, "Just so, just so. You are the honest one."
正是 doubled is agreement offered without much thought. 還 is hái, the still or after all reading — you are the honest one, when it comes to it — and it is the most dangerous sentence in the chapter, because Tripitaka is about to act on it.
Bajie's argument is a real piece of rhetoric and it works by conceding everything. His brother is better at transformations, at tricks, at making fools of people — three admissions, delivered fast, so the listener stops guarding.
Then the pivot. Honesty is a different category, and on that one he is not merely better but better by regiments. The image is absurd on purpose: you cannot line a man up in ranks and add his honesty together.
Tripitaka agrees immediately, which is the problem. He has just been given four unanswered questions and a volunteer, and the volunteer's entire qualification is that he says he is honest.