未卜先知 Knowing Without Casting Lots
及到方丈，眾僧俱來叩頭，問道：「列位老爺像貌不一，可是東土大唐來的麼？」行者笑道：「這和尚有甚未卜先知之法？我們正是。你怎麼認得？」及到方丈，众僧俱来叩头，问道：「列位老爷像貌不一，可是东土大唐来的么？」行者笑道：「这和尚有甚未卜先知之法？我们正是。你怎么认得？」
逐句解 Line by line
When they came to the abbot's quarters the monks all knocked their heads on the ground and asked, "Your Reverences are not alike in feature. Can it be that you have come from the Land of the East, from the Great Tang?"
像貌不一, not alike in feature, is the observation that gets them recognised — a monkey, a pig, a dark-faced man and an ordinary priest travelling together are not a party anybody could mistake. The 一 stands at the end of its clause, and by the standing rule a clause-final 一 keeps yī rather than shifting for whatever follows.
Pilgrim laughed. "What art of knowing-without-divining have these monks got?
未卜先知 is knowing a thing before you have cast the milfoil stalks or cracked the shell for it: foreknowledge with no divination behind it, and still what Chinese reaches for when somebody guesses right. 甚 is the question-word here, shén, standing in for 什麼, and not the intensifier shèn it is a few lines later.
"We are indeed. How did you know us?"
認得 takes the full dé: the character is carrying its own verb of recognising, not linking one verb to another. Nine characters, and Pilgrim has conceded the point and asked his own question in the same breath.
The monks knew them before anybody told them, and Pilgrim's first response is suspicion dressed as a joke. He has spent the chapter so far being the one who reads a situation right from a distance, and here somebody has read him.
The question is worth asking. A party recognised on sight in a foreign capital where none of them has ever been is either famous or expected, and being expected, in this novel, usually means something supernatural has been at work. The answer, when it comes, is exactly that.