三更時分 To The Third Watch
在那半空中，一來一往，一上一下，鬥到三更時分，未見勝敗。八戒、沙僧在李家天井裡看得明白。原來那怪只是舞槍遮架，更無半分兒攻殺。行者一條棒不離那怪的頭上。八戒笑道：「沙僧，你在這裡護持，讓老豬去幫打幫打，莫教那猴子獨幹這功，領頭一鍾酒。」在那半空中，一来一往，一上一下，斗到三更时分，未见胜败。八戒、沙僧在李家天井里看得明白。原来那怪只是舞枪遮架，更无半分儿攻杀。行者一条棒不离那怪的头上。八戒笑道：「沙僧，你在这里护持，让老猪去帮打帮打，莫教那猴子独干这功，领头一钟酒。」
逐句解 Line by line
There in the middle air, one coming and the other going, one above and the other below, they fought until the third watch and no advantage showed either way.
更 is gēng here, the night watch — the Chinese night was divided into five of them — against the gèng, "still more," it took twice in the passage before. The four appearances of 一 form a doubled back-and-forth pattern and take their ordinary tone slide throughout, two one way and two the other.
Eight Rules and Sha Monk could see it all plainly from Li's courtyard.
The watchers can see, and the verb says so with weight: 看得明白 pairs "look" with 得 as the full verb dé — they got a clear view of it. What they got a clear view of is the point of the passage.
It turned out that the creature only whirled its spear to parry, and made not half a fraction of an attack.
更 goes back to gèng two segments after taking gēng. 半分兒 is the smallest quantity imaginable — "not half a scrap."
Pilgrim's single rod never left the creature's head.
一條 takes its ordinary tone slide before a rising tone.
Eight Rules laughed and said, "Sha Monk, you keep guard here and let old Pig go and lend a hand or two. We are not having that monkey do the whole deed by himself and take the first cup of wine."
The chapter's one genuinely tricky 一. In 頭一 it is an ordinal — "the very first" — so it keeps its plain tone yī instead of sliding into the character after it, the way a counting 一 normally would. The parse is 領 + 頭一鍾酒, because 領頭 ("to lead off") cannot take an object, so the phrase has to break the other way. This is the only place in the chapter where the reading has to be fixed by hand.
The fight is summarised rather than staged: eight characters of movement in four paired units, a time, and a verdict of no result. What the passage is actually interested in is what the watchers can see from the courtyard.
And what they can see is that the creature has not attacked once. It parries and does nothing else, from the challenge until the third watch, while Pilgrim's rod never leaves its head. That is the first solid fact about the thing that has not come from a villager, and it does not fit anything the villagers said.
Eight Rules draws exactly the wrong conclusion. Seeing a stalemate, he decides the danger is low enough to join in — and says so in terms of credit and reward rather than of help. Nobody has offered any wine: the character 酒 occurs precisely once in this chapter, and it is here, in his complaint about who would get it.