晚輩小仙 The Junior Immortals' Ruse
八戒聞言，心中忐忑，默對行者道：「這是我們的不是：吃了東西，且不走路，只等這般禱祝。卻怎麼答應？」行者又捻一把，忽地開口，叫聲：「晚輩小仙，且休拜祝。我等自蟠桃會上來的，不曾帶得金丹聖水，待改日再來垂賜。」那些大小道士聽見說出話來，一個個抖衣而戰道：「爺爺呀！活天尊臨凡，是必莫放，好歹求個長生的法兒。」八戒闻言，心中忐忑，默对行者道：「这是我们的不是：吃了东西，且不走路，只等这般祷祝。却怎么答应？」行者又捻一把，忽地开口，叫声：「晚辈小仙，且休拜祝。我等自蟠桃会上来的，不曾带得金丹圣水，待改日再来垂赐。」那些大小道士听见说出话来，一个个抖衣而战道：「爷爷呀！活天尊临凡，是必莫放，好歹求个长生的法儿。」
逐句解 Line by line
Bajie, hearing this, grew flustered at heart and whispered aside to Pilgrim, “This is our own doing: we ate the things and, instead of hitting the road, sat waiting for just such a prayer as this.
心中: 中 = zhōng. 行者: 行 = xíng. 我們的不是 "our fault, our wrong" -- 不是 used as a noun, a thing you can possess. 禱祝 "to pray, to invoke."
How are we to answer them?”
答應: 應 = yìng, to answer back, not yīng, "ought to" -- pypinyin reaches for the wrong one here.
Pilgrim gave him another pinch, then suddenly opened his mouth and called out, “You juniors of the immortal ranks, cease your prostrations for a moment.
行者: 行 = xíng. 捻一把: the third tone of 把 keeps 一 at yì. 晚輩小仙 "you juniors of the immortal ranks" -- Wukong has been a god for about four seconds and is already talking down to the clergy.
We have come straight from the Feast of the Peaches and did not bring golden elixir or holy water along; wait another day and we shall come again to bestow it.”
蟠桃會 the Feast of Immortal Peaches, held in the Jade Emperor's heaven -- and, as it happens, the banquet Wukong wrecked some forty chapters back, so of all the excuses available this is the one he can improvise from memory. 不曾帶得: 得 = dé, to have brought or obtained; the rising tone of 曾 keeps 不 at bù.
The Daoists, great and small, hearing a voice speak out, each shook in his robes and cried out, trembling, “Venerable Fathers!
那些: 那 = nà. 一個個: the falling tone of 個 pulls 一 to yí. 抖衣而戰 "to shake inside one's clothes" -- trembling so hard the robe moves.
A living Venerable has come down among mortals — we must by no means let him go; come what may, let us beg some means of everlasting life!”
臨凡 "to come down among mortals." 好歹 "come what may, by hook or by crook." 長生: 長 = cháng. 法兒 "a method, a way of doing it"; 兒 = er, the curled ending on the word.
Bajie panics, which is his function, and Wukong improvises, which is his. The pinch comes first -- keep still -- and then a voice from the statue, claiming to have come straight from the Peach Banquet and to have left the elixir at home.
It is the oldest excuse there is, and it works because the Daoists are not testing the claim, they are hoping for it. Their terror is completely sincere. That is what makes the scene funny rather than merely cruel: years of certainty about their standing with heaven have left them with no way at all to tell a god from a monkey doing a voice.