尸山血海 Only The Monkey King Walks In
逐句解 Line by line
A mountain of corpses indeed, a sea of blood, and the reek of it past bearing.
尸山血海 is still current Chinese for a scene of slaughter, the way English reaches for "bloodbath." 真個是 and 果然 are the narrator stepping in to vouch for it: really, truly, no exaggeration. He protests slightly too much, which is how you know the poet enjoyed writing it.
Off east the lesser fiends were seizing men alive and slicing the flesh from them; away west the foul demons had human meat fresh in the pot, fresh on the boil.
These two halves are printed as one sentence split by a semicolon, and they fold back together here because they match at every joint: direction for direction, demon for demon, 將 answered by 把 — both of them the grammar that shoves an object in front of its verb — and a four-character verb phrase closing each side. 剮 guǎ is the slicing punishment, the one reserved for the worst crimes on the imperial books; here it is simply how lunch is prepared.
Had the Handsome Monkey King not carried a heart this bold, no second mortal alive would have got in through that door.
The rhapsody closes by naming its own hero, which is the standard way these set-pieces sign off. 進不得 puts 得 in its light, unstressed form de — the "can't manage to" grammar rather than the full verb dé, "to get." The sealed chapters are lopsided about this: after a real verb, this shape is de almost every time — 轉身不得, 動不得, 近不得, 認不得 — and the dé readings all belong to a different construction entirely.
The closing couplet is doing publicity. Having spent five lines making the cave as revolting as language allows, the poem turns and uses all of it as a compliment: any ordinary man would have stopped at the threshold. It is the oldest trick in adventure writing and it still works, because the horror was real first.
Note who is being praised. Not the pilgrim, not the mission — the 美猴王, the Handsome Monkey King, the title Wukong gave himself on Flower-Fruit Mountain in the book's first chapter, long before anybody put a headband on him. When the book wants to say he is being brave rather than obedient, it reaches back for the old name.