父子之仇 A Teacher for a Day
行者道：「你這個潑怪，豈知『一日為師，終身為父』？『父子無隔宿之仇』？你傷害我師父，我怎麼不來救他？你害他便也罷？卻又背前面後罵我，是怎的說？」妖怪道：「我何嘗罵你？」行者道：「是豬八戒說的。」那怪道：「你不要信他。那個豬八戒尖著嘴，有些會說老婆舌頭，你怎聽他？」行者道：「你这个泼怪，岂知『一日为师，终身为父』？『父子无隔宿之仇』？你伤害我师父，我怎么不来救他？你害他便也罢？却又背前面后骂我，是怎的说？」妖怪道：「我何尝骂你？」行者道：「是猪八戒说的。」那怪道：「你不要信他。那个猪八戒尖着嘴，有些会说老婆舌头，你怎听他？」
逐句解 Line by line
Pilgrim said, "You vile fiend — what should you know of 'a teacher for a single day is a father for a lifetime'?
And here the proverb comes back. 一日為師，終身為父 — "a teacher for a single day is a father for a lifetime" — is the exact line Bajie used on him near the start of the chapter, quoting the White Dragon Horse. Wukong was moved by it there; he wields it as a weapon here.
Or of 'between father and son no grudge lasts overnight'?
The second maxim follows from the first. 父子無隔宿之仇, fù zǐ wú gé sù zhī chóu, "between father and son no grudge lasts overnight" — 隔宿, gé sù, over a night. Having made Tripitaka a father by the first proverb, he uses the second to cancel the quarrel. It is a neat piece of reasoning, and it is also how he lets himself off having been thrown out.
You have done my master harm — how should I not come to save him?
傷害, shāng hài: to injure, to do harm to.
That you harmed him might be let pass—
便也罷, biàn yě bà, "that might have been let pass." Watch what he is about to say is worse than harming his master.
but that you should revile me behind my back and to my face besides — what account is there of that?"
背前面後, bèi qián miàn hòu, behind the back and to the face alike — the same phrase he used on the crag. Kidnapping Tripitaka was forgivable; the insult was not. The chapter has been honest about this from the start.
The fiend said, "When did I ever revile you?"
何嘗, hé cháng, "when did I ever?" — and the answer, which only the reader knows, is never.
Pilgrim said, "It was Zhu Bajie who told me."
Six words, and the whole quarrel rests on them.
The fiend said, "Do not believe him.
信, xìn: to believe, to trust.
That Zhu Bajie, with his jutting snout, is something of a tale-bearer — how can you heed him?"
尖著嘴, jiān zhe zuǐ, with the snout stuck out — the "-ing" form. 老婆舌頭, lǎo pó shé tou, "an old wife's tongue," meaning idle gossip and tale-bearing. The demon's assessment of Bajie is not only shrewd, it is exactly right — and Wukong will not hear it.
Wukong grounds his return in two proverbs of the filial bond — the teacher who is a father for life, the father and son whose quarrels do not survive a night — the very commonplaces Bajie used on him at the start of the chapter, now turned outward as the justification of the rescue. The rhetoric dignifies what is, at bottom, a matter of wounded pride: he can forgive harm done to his master more readily than an insult to himself.
The turn to the reported insult exposes the true spring of his fury, and the demon's denial quietly confirms what the reader has known for fifty passages: the whole tirade was Bajie's invention. The fiend's counter, that Bajie is a tale-bearer with a gossip's tongue, is nearer the mark than he can possibly know, and gives the confrontation a last twist of irony before it turns to blows.