兩山不住 Two Mountains Will Not Hold Him
這個倒也不怕，只是正擔好挑，偏擔兒難挨。」那魔道：「一座山壓他不住。」卻又念咒語，把一座峨嵋山遣在空中來壓。行者又把頭偏一偏，壓在右肩臂上。这个倒也不怕，只是正担好挑，偏担儿难挨。」那魔道：「一座山压他不住。」却又念咒语，把一座峨嵋山遣在空中来压。行者又把头偏一偏，压在右肩臂上。
逐句解 Line by line
“This one, though, I don't fear — only a balanced load is easy to shoulder, while a lopsided load is hard to bear.”
倒 (dào) here is the adversative, “though, on the contrary.” 正擔／偏擔 (zhèng dàn / piān dàn), “a level load / a lopsided load,” 擔 the noun dàn, “burden”; 挨 (āi), “to bear, endure.” Pilgrim frames a mountain as a mere carrying problem.
The fiend said: “One mountain won't hold him down.”
壓他不住 (yā tā bù zhù), “cannot press him down and hold him.” The demon, seeing the first peak fail, resolves to add a second.
So again he chanted his spell and sent a Mount Emei through the air to crush him.
咒語 (zhòu yǔ), “an incantation, spell.” 峨嵋山 is Mount Emei, one of the great sacred peaks of Sichuan — the second of the three mountains loosed on Pilgrim.
Pilgrim again tilted his head to one side, and it came down on his right shoulder.
偏一偏 (piān yì piān), “to tilt just so, give a slight cant.” Now Pilgrim bears a peak on each shoulder, the burden mounting toward the breaking point.
Pilgrim shrugs off the first mountain with a workman's complaint — a balanced load is easy, a lopsided one is not — and the demon, undeterred, answers by adding Mount Emei to the first. The passage keeps the contest in the register of comedy: the Great Sage treats world-peaks as freight to be balanced across his shoulders, and the fiend piles them on with a plodding, literal logic (“one mountain won't hold him”).
Beneath the comedy, the escalation is exact and ominous. One peak on the left, a second on the right: the tally is being kept, and the reader senses a third is coming. The scene's method is the folk-tale rule of three, each mountain heavier than plausibility allows, building the pressure toward the moment when even Monkey's strength must give — and with it, his power to protect the Master who has walked on ahead.