有詩為證 A Poem in Witness
三藏才與八戒、沙僧前走，行者背著孩兒隨後，一行徑投西去。有詩為證。詩曰：三藏才与八戒、沙僧前走，行者背着孩儿随后，一行径投西去。有诗为证。诗曰：
逐句解 Line by line
Tripitaka had just gone on ahead with Eight Rules and Sha Monk, and Pilgrim, bearing the child, followed behind, the whole company pressing straight on westward. There is a poem in witness. The poem says:
三藏: 藏 = zàng. 背著孩兒: durative 著 = zhe; standalone 兒 (孩兒) = ér. 一行: 行 = xíng. 有詩為證: 為 = wéi (為證 "in witness," via BIGRAM_PY).
As the Way of virtue mounts high, so the demon-barriers mount high; the Chan-spring is of itself still, and from stillness the demon is born.
道德高隆魔障高 / 禪機本靜靜生妖: the couplet's paradox — spiritual attainment (道德, 禪機) itself calls forth its adversary (魔障, the demon-obstacle), and the demon arises precisely from the stillness that cultivation seeks.
The heart-sovereign, upright and true, walks the central Way; the Wood-Mother, foolishly stumbling, is stubborn without and nimble.
心君 = the "heart-sovereign," i.e. the 心猿 Wukong; 行中道: 行 = xíng, 中 = zhōng ("the middle Way"). 木母 = the "Wood-Mother," i.e. Bajie (八戒); 痴屣頑外趫 renders his foolish, shuffling, outwardly-agile nature (趫 = qiáo, "nimble").
The Will-Horse, saying nothing, harbors love and desire; the Yellow Dame, wordless, frets alone.
意馬 = the "Will-Horse," the dragon-horse (意馬 as the untamed will); 黃婆 = the "Yellow Dame," the mediating earth-agent of internal alchemy — together with 心君 and 木母 this couplet completes the five-agents (五行) allegory of the party's inner faculties.
The guest-heresy, having gained its aim, rejoices in vain; in the end it will yet be dissolved by the orthodox.
客邪 = the "guest-heresy," the intruding demon as a foreign, transient corruption; 得志: 得 = dé. 畢竟還從正處消: 還 = hái ("in the end, still"); 處 = chù — the demon's triumph is temporary, doomed to be resolved by the 正 (the orthodox / the true).
The poem is one of the chapter's dense knots of internal-alchemy (內丹) allegory, and it recasts the whole comic sequence just concluded as a diagram of the cultivating self under assault. Its governing paradox is stated in the opening couplet: spiritual attainment does not banish the demonic but summons it — 道德高隆魔障高 ("as the Way of virtue mounts high, so the demon-barriers mount high") — and the demon is born, disturbingly, from the very stillness (靜) that Chan practice seeks. The Red Boy is thus figured not as an external accident but as the necessary shadow of the pilgrims' own advancing discipline.
The middle couplets map the party onto the standard five-agents (五行) scheme that the novel sustains throughout: 心君 (the "heart-sovereign") is Wukong the mind-monkey, upright and holding the central Way; 木母 ("Wood-Mother") is Bajie; 意馬 ("Will-Horse") is the dragon-horse; and 黃婆 ("Yellow Dame") is the mediating earth-agent that binds the others. Each is given a failing or a limit — Bajie's stubborn foolishness, the Horse's harbored desire, the Dame's helpless fretting — so that the demon's momentary success (客邪得志, "the guest-heresy gains its aim") is shown to exploit real weaknesses in the compound self. The closing line delivers the poem's consolation and the arc's promise in one stroke: 畢竟還從正處消 ("in the end it will yet be dissolved by the orthodox") — the intrusion is transient, and the orthodox (正) will prevail, however long the ordeal of Chapters 40 through 42 must run before it does.