蜻蜓撼石柱 Like Dragonflies Shaking a Stone Pillar
沙僧將寶杖拋出,倚在牆邊。二王子與三王子跳起去便拿,就如蜻蜓撼石柱,一個個掙得紅頭赤臉,莫想拿動半分毫。沙僧将宝杖抛出,倚在墙边。二王子与三王子跳起去便拿,就如蜻蜓撼石柱,一个个挣得红头赤脸,莫想拿动半分毫。
逐句解 Line by line
Sha Monk tossed his treasure staff out and stood it leaning against the wall.
Sha Monk props his against the wall where Bajie dropped his on the floor, which is entirely in character for the tidiest member of the party. 倚 is to lean something against a support.
The second and third princes sprang up to take hold of them, and it was like dragonflies trying to shake a stone pillar. Every one of them strained till his head and face went scarlet, and there was no hope of shifting them by half a hair.
The image is the best in the chapter. 蜻蜓撼石柱 — a dragonfly shaking a stone pillar — sets the lightest thing anyone can picture against the heaviest, and the joke is in the verb: the dragonfly is genuinely trying. 掙 is zhèng here, to strain, and 得 is de, tying the straining to the scarlet faces. 莫想, do not even think of it, is the same fixed shape used when the eldest prince failed at the rod.
The novel has been building to this image and it is worth stopping on. A dragonfly landing on a stone pillar and heaving is exactly the shape of what is happening, down to the good faith of the attempt.
Note that these are strong boys who have trained all their lives, and the text says so twice. Their failure is not weakness. It is a difference in kind, and the next few pages are about how that difference gets crossed.