一把揪住 Seized and Questioned
行者上前，一把揪住道：「你過來，等我問你。」獃子又慌了，戰戰兢兢的道：「問便罷了，揪扯怎的？」行者道：「是甚麼山？」八戒道：「是石頭山。」「甚麼洞？」道：「是石頭洞。」「甚麼門？」道：「是釘釘鐵葉門。」「裡邊有多遠？」道：「入內是三層。」行者上前，一把揪住道：「你过来，等我问你。」呆子又慌了，战战兢兢的道：「问便罢了，揪扯怎的？」行者道：「是甚么山？」八戒道：「是石头山。」「甚么洞？」道：「是石头洞。」「甚么门？」道：「是钉钉铁叶门。」「里边有多远？」道：「入内是三层。」
逐句解 Line by line
Pilgrim stepped up, seized him with one grab, and said: "Come here — let me question you."
一把揪住, yì bǎ jiū zhù, "grabbed him in one" — 揪 is to seize by the hair or the collar. The interrogation is now physical.
The blockhead panicked again and said, trembling: "Ask, then, and be done — what's all this grabbing and pulling?"
戰戰兢兢, zhàn zhàn jīng jīng, "shaking and quaking" — from the Book of Odes, and still the standard four-character phrase for someone walking on eggshells. 揪扯, "grabbing and hauling."
Said Pilgrim: "What mountain is it?"
甚麼山 — 甚 read shén. Question one, and it is word for word the question he prepared for.
Said Eight Rules: "It's Stone Mountain."
石頭山, shí tou shān. Answer one, delivered exactly as drilled to the rocks.
"What cave?" "It's Stone Cave."
甚麼洞 — 甚 read shén. The narration has stopped bothering with speaker tags, which speeds the exchange up into a proper cross-examination rhythm.
"What gate?" "It's a nail-studded iron-plate gate."
釘釘鐵葉門, dīng dīng tiě yè mén, the nail-studded iron gate. 甚 is shén. Three for three.
"How far does it run inside?" "Within, there are three chambers."
入內是三層, rù nèi shì sān céng, "three chambers within." Four for four — and every correct answer digs the hole deeper, because Pilgrim is not asking in order to find out.
The guard is down and the questioning turns physical: Pilgrim seizes him bodily and starts asking. What follows is staged as rapid call-and-response, and the narration strips out the speaker tags to speed it up — what mountain, what cave, what gate, how far in — with the answers coming back in exactly the words drilled to the rocks. Stone Mountain. Stone Cave. Iron gate with nails. Three chambers.
The comedy is entirely in the pig's obliviousness. He thinks he is passing a test; four correct answers in, he may even be feeling pleased. But Pilgrim is not gathering information — he has all of it — and every reply that matches the script is another turn of the screw. This is not an interrogation. It is a witness being walked to the point where he will condemn himself in his own words.