心淨孤明 The Mind at Rest Shines
行者道：「不消說了。心淨孤明獨照，心存萬境皆清。差錯些兒成惰懈，千年萬載不成功。行者道：「不消说了。心净孤明独照，心存万境皆清。差错些儿成惰懈，千年万载不成功。
逐句解 Line by line
Pilgrim said, "No need to say more.
不消 is the vernacular for no need — the everyday phrase, dropped in just before he launches into four lines of perfectly balanced preaching.
The mind made clean shines alone with a solitary brightness; the mind held steady, and every realm around it is clear.
Two lines of six characters, matched clause for clause — 心淨 against 心存, brightness against clarity. This is not vernacular speech any more; Pilgrim has shifted into the language of a manual. 萬境 is all the realms of experience, everything the senses bring in.
Go a little wrong and it turns to sloth; a thousand years, ten thousand years, and still nothing achieved.
載 is zǎi, a year — not the zài of carrying a load. 惰懈 pairs two words for slackness, and the warning is about degree: not a wrong turn but 些兒, a little bit, which is enough.
Pilgrim in doctrinal mode is a genuinely odd sight, and the novel never explains where he learned it. He spent five hundred years under a mountain and came out able to quote.
The threat in the last line is time, not danger. Not you will be eaten, but you will still be at this in ten thousand years. For a party on a road that has already taken them most of a lifetime, that lands harder than a demon would.