邪正分明 One Changes Face One Grows
逐句解 Line by line
The one changes his face as his heart wills; the other plants his feet and grows in body and waist.
更 is gēng here, to change or alter — not the gèng of even more. 長 is zhǎng, to grow. Two magics, one to each fighter: transformation against sheer size.
They fought till the sky was heavy with cloud-vapour and mist streamed over all the moor.
殺得 puts 得 in the light de — fought so that. This unit is shorter than its neighbours, seven and five instead of seven and seven, and the rhapsody form permits that where strict verse would not.
That one has set his mind again and again on eating Xuanzang; this one widely wields his powers to guard the house of Tang.
The longest unit in the poem, and it drops the balanced short lines for two long ones — 那一個 against 這一個, that one and this one, which is the rhapsody naming its sides.
All because the Buddha handed down the scriptures, crooked and straight stand clear, and hatred and bitterness meet.
邪正分明 — the crooked and the upright plainly distinguished. The poem ends by putting the whole brawl down to the Buddha deciding to send scriptures east, which is both the plot of the novel and, in context, a slightly wry remark.
The closing couplet does something the fight itself never does: it explains why anybody is here. A demon wants to eat a monk, a monkey is paid to stop him, and the whole arrangement exists because a Buddha decided some texts should travel. Stated that flatly it sounds less like destiny than like logistics.
恨苦交, hatred and bitterness meeting, is the last phrase and it refuses to take a side. The poem has just spent six units keeping the two combatants exactly balanced, half-line for half-line, and it declines at the end to say which of them is the crooked one — while making perfectly clear that it knows.