不識起倒 He Knows Not Rising From Falling
大聖道：「既蒙寬恩，感謝不盡。但尚有一事奉瀆，萬望周濟周濟。」牛王罵道：「這猢猻不識起倒，饒了你，倒還不走，反來纏我。甚麼周濟周濟？」大圣道：「既蒙宽恩，感谢不尽。但尚有一事奉渎，万望周济周济。」牛王骂道：「这猢狲不识起倒，饶了你，倒还不走，反来缠我。甚么周济周济？」
逐句解 Line by line
The Great Sage said, "Since I have received so generous a pardon, my thanks are beyond telling."
不盡 is where two tone rules collide. 盡 is held at jìn throughout this project, but the automatic tone change that decides whether 不 is bù or bú runs on the character's dictionary reading — which is jǐn, a dipping tone. So the machinery produces bù where the actual reading requires bú, and the correction has to be made by hand. It is one of only two such collisions in the chapter.
"But there is yet one matter with which I must trouble you, and I earnestly beg your help in it, your help in it."
奉瀆 is the humble form for imposing on a superior — literally, to sully them by offering. 一事 takes yí before the falling tone of 事. And keep an ear on the doubled 周濟周濟: it comes straight back at him in the next sentence.
The Bull King railed, "This ape does not know rising from falling! I let you off, and instead of going you turn back and pester me. What help, what help?"
倒 takes both its readings four characters apart. In 起倒 it is dǎo, the falling that pairs with the rising, and the idiom 不識起倒 means to have no sense of when to stop pushing; in 倒還不走 it is dào, the adverb of the-other-way-round. 甚 is shén.
The Great Sage has been pardoned and immediately asks for a favour, and the Bull King's exasperation is the most human note he is given in the chapter. 不識起倒 — he cannot tell rising from falling — is exactly right: the Great Sage has no instinct at all for the moment when an advantage has been pushed as far as it will go.
The passage turns on one repeated phrase. 周濟周濟, begged in the second sentence, comes back as 甚麼周濟周濟 in the third, and the doubling that was deferential in the asking is contemptuous in the echo. The novel uses this trick constantly in quarrels — the opponent's own words handed back with the courtesy stripped out — and used it earlier in this same chapter when the Great Sage turned 陪 round on the Jade-Faced Princess.