心無罣礙 No Obstruction in the Mind
師徒們正行賞間，又見一山擋路。唐僧道：「徒弟們仔細，前遇山高，恐有虎狼阻擋。」行者道：「師父，出家人莫說在家話。你記得那烏巢和尚的《心經》云『心無罣礙：無罣礙，方無恐怖，遠離顛倒夢想』之言？但只是：『掃除心上垢，洗淨耳邊塵。不受苦中苦，難為人上人。』你莫生憂慮，但有老孫，就是塌下天來，可保無事，怕甚麼虎狼？」师徒们正行赏间，又见一山挡路。唐僧道：「徒弟们仔细，前遇山高，恐有虎狼阻挡。」行者道：「师父，出家人莫说在家话。你记得那乌巢和尚的《心经》云『心无罣碍：无罣碍，方无恐怖，远离颠倒梦想』之言？但只是：『扫除心上垢，洗净耳边尘。不受苦中苦，难为人上人。』你莫生忧虑，但有老孙，就是塌下天来，可保无事，怕甚么虎狼？」
逐句解 Line by line
As master and disciples went along savoring the view, once again a mountain rose to block their way.
Spring is over; the plot resumes. 賞間, shǎng jiān, "while they were taking in the view"; 擋路, "to block the road." A mountain across the way is this novel's standard signal that trouble is about to start.
Said the Tang Monk: "Take care, disciples. A high mountain lies ahead, and I fear tigers and wolves may bar our passage."
The Tang Monk's reflex, as always, is fear. 仔細, zǐ xì, "watch out, be careful" — worth flagging that 仔 is zǐ here, not the zǎi a modern reader (or a modern piece of software) would guess first.
Said Pilgrim: "Master, one who has left the household life should not talk as householders do.
出家人, chū jiā rén, is literally "one who has left the household" — a monk. 在家話 is its opposite number, "householder talk," the sort of thing ordinary worried people say. Pilgrim is telling his master to stop talking like a layman.
Do you recall the words of that Crow's-Nest monk's Heart Sūtra? — 'In the mind there is no obstruction; being without obstruction, one is then without dread, and leaves far behind all inverted, dreamlike thinking.'
And then the monkey quotes scripture at the monk. 烏巢, Wū cháo, is the Crow's-Nest Zen Master, who handed the Heart Sūtra (《心經》) to the pilgrims earlier in the journey, in chapter 19. 罣礙, guà ài, is "obstruction, snag"; 顛倒 is "upside-down, inverted," with 倒 read dǎo. In 記得 the 得 is the light de; 那 is nà. The line he picks is the Sūtra's own promise that a mind with nothing snagging it has nothing to dread — aimed squarely at a master who is dreading everything.
It is only this: 'Sweep away the grime upon the mind; wash clean the dust beside the ear. He who will not bear the bitterest of bitters can never be a man above other men.'
Having quoted the Sūtra, he tops it off with a proverb. 苦中苦, kǔ zhōng kǔ, "the bitterest of the bitter"; 難為, "hard to become," where 為 is wéi and 中 is zhōng. Chinese still says this one, in the slightly smoother form 吃得苦中苦，方為人上人 — no pain, no promotion. Pilgrim has just welded a Buddhist sūtra to a piece of pure worldly grit and handed the result to his teacher.
Breed no anxieties. So long as Old Sun is here, even were the sky to come crashing down I can keep you from harm — what are a few tigers and wolves to fear?"
塌下天來, tā xià tiān lái, "even if the sky caves in"; 怕甚麼, pà shén me, "what is there to be afraid of?" — with 甚 read shén. Scripture, proverb, and now swagger, all inside one speech.
A mountain blocks the road, the Tang Monk starts worrying about tigers and wolves, and his monkey disciple answers him by quoting the Heart Sūtra. That is the joke, and it is a durable one: the thief, brawler and ex-convict of the party turns out to be the best Buddhist in it. The line he chooses is 心無罣礙, "nothing snagging the mind," and the Sūtra's claim that an unsnagged mind has nothing to be frightened of and no 顛倒夢想, no upside-down dreaming. It is aimed straight at a master whose mind is snagged on tigers.
He then splices scripture to street wisdom — 不受苦中苦，難為人上人, no bitterness, no rising in the world — and finishes on pure bluster: with Old Sun here, the sky could fall in. Note that the reader's edition keeps both the sūtra line and the proverb as prose inside his speech, because the text does not set them off as a poem; they are quotations in dialogue, not verse.