賺鎖山門 A Plan to Lock the Pilgrims In
若是與他分說，那廝畢竟抵賴，定要與他相爭；爭起來，就要交手相打，你想我們兩個怎麼敵得過他四個？且不如去哄他一哄，只說果子不少，我們錯數了，轉與他陪個不是。他們的飯已熟了，等他吃飯時，再貼他些兒小菜。他一家拿著一個碗，你卻站在門左，我卻站在門右，撲的把門關倒，把鎖鎖住，將這幾層門都鎖了，不要放他，待師父來家，憑他怎的處置。他又是師父的故人，饒了他，也是師父的人情；不饒他，我們也拿住個賊在，庶幾可以免我等之罪。」清風聞言道：「有理，有理。」若是与他分说，那厮毕竟抵赖，定要与他相争；争起来，就要交手相打，你想我们两个怎么敌得过他四个？且不如去哄他一哄，只说果子不少，我们错数了，转与他陪个不是。他们的饭已熟了，等他吃饭时，再贴他些儿小菜。他一家拿着一个碗，你却站在门左，我却站在门右，扑的把门关倒，把锁锁住，将这几层门都锁了，不要放他，待师父来家，凭他怎的处置。他又是师父的故人，饶了他，也是师父的人情；不饶他，我们也拿住个贼在，庶几可以免我等之罪。」清风闻言道：「有理，有理。」
逐句解 Line by line
"If we argue it out with him, that fellow will only deny it flatly and be bent on quarreling; and once it comes to quarreling, we shall come to blows—and how are the two of us to get the better of the four of them?
Bright Moon does the arithmetic out loud: two boys against four travellers, three of them armed. 分說, fēn shuō, is arguing your case out. 相爭, xiāng zhēng, and 相打, xiāng dǎ, are contending and fighting with each other — 相 in its mutual sense, xiāng, not the xiàng that means "appearance." 敵得過, dí de guò, is "to be a match for," with the toneless linking 得, de.
"Better, then, to go and cozen him: say only that the fruits are not short—that we miscounted—and turn round and make him our apologies.
So guile instead. 哄他一哄, hǒng tā yì hǒng, is to sweet-talk somebody along. 錯數了, cuò shǔ le, "miscounted," with 數 as the verb shǔ. 陪個不是, péi gè bú shì, is to offer an apology — and note that 不是 here is a noun, "a fault," not the negative "is not."
"Their meal is already cooked; when they sit to eat, we shall lay on a few more side-dishes for them.
The bait is hospitality: a few extra dishes with the rice. 貼 is "to add on, throw in extra," and 些兒 takes the diminutive suffix 兒, ér.
"Each of the household will be holding a bowl; you stand at the left of the door, I at the right, and with a bang we slam the door to, drop the lock, and bar every one of these several gates. Do not let them out—wait until the master comes home, and let him deal with them as he will.
The trap, laid out step by step like stage directions. 撲的把門關倒, pū de bǎ mén guān dǎo, is slamming the door to with a bang, 關倒 taking 倒 as dǎo. 將這幾層門都鎖了 locks every gate in turn, with 將, jiāng, the little word that puts the object up front before the verb, and 都, dōu, "all."
"He is besides an old acquaintance of the master's: to spare him will be the master's own kindness, and not to spare him—why, we shall have a thief in hand, and that may serve to clear the two of us of blame."
The clinching argument, and it is the reasoning of a servant who cannot lose either way. 故人, gù rén, is "an old acquaintance" — the abbey's master and Tang Sanzang were sworn friends, which is why the pilgrims were made welcome at all. 庶幾 is a bookish "so that we may perhaps," lifted from written formality rather than kitchen talk. 免我等之罪, miǎn wǒ děng zhī zuì, is "clear the two of us of blame."
Clear Wind, hearing him out, said, "That is sound, that is sound."
聞言, wén yán, "on hearing this." 有理, yǒu lǐ, "that stands to reason" — doubled, as everything the two of them say gets doubled.
Bright Moon's plan is a small masterpiece of the weak. He cannot outfight four armed travellers and says so plainly, so he proposes to disarm them with courtesy instead: apologise, admit the miscount, lay on extra dishes, and bolt the doors while everybody has both hands on a rice bowl.
What makes it work as a plan is the hedge at the end. Sanzang is the master's 故人, his old friend, so if the master forgives the monks that is his own business and no fault of theirs; and if he does not, the boys will have handed him the culprits. Either way the two of them are covered. It is exactly how a junior employee thinks about a disaster that happened on their shift.
Clear Wind's doubled 有理，有理 gives assent without adding a thought, which is his function throughout: the elder in rank, the follower in fact.