個大恭也 Tomorrow You Will Be Dung
那怪來吃你，你如何不走，反去迎他！這一口吞在肚中，今日還是個和尚，明日就是個大恭也。」那魔得勝而去，這獃子才鑽出草來，溜回舊路。那怪来吃你，你如何不走，反去迎他！这一口吞在肚中，今日还是个和尚，明日就是个大恭也。」那魔得胜而去，这呆子才钻出草来，溜回旧路。
逐句解 Line by line
"The creature comes to eat you and you don't run — you go up to meet him instead!"
The exclamation is the book's. Bajie is genuinely upset, and he is also, from under a bush, delivering tactical criticism to somebody who cannot hear him.
"Swallowed down at a mouthful like that — today he is a monk, tomorrow he will be a movement of the bowels."
還 is hái, still. And 大恭 is the same prim examination-hall euphemism Wukong used about the bottle a few thousand characters ago — the wooden tablet marked gōng that a candidate carried when he left the hall. Bajie is being crude in the politest available register.
The fiend went off victorious, and only then did the Idiot bore his way out of the grass and slip back the way he had come.
得 keeps the full dé at 得勝, to win. And 鑽出草來 is the chapter's sixteenth 鑽: Bajie bores out of the grass exactly as Wukong bored out of the bottle, and the same character stands in the chapter's title.
The joke is real and so is the grief underneath it. Bajie has just watched his brother be eaten, and what comes out of him is a crack about what will be left by tomorrow. It is how he handles everything, and the book has never once suggested he does not mean both halves.
大恭 connects two scenes across the whole chapter. Wukong told the demons their bored-through treasure was only fit to squat over; Bajie now says the same thing about Wukong. The novel is fond of these small returns, and it rarely points at them.