解了餘毒 The Last of the Poison
那星官用手把嘴唇上摸了一摸，吹一口氣，就不疼了。獃子歡喜下拜道：「妙啊！妙啊！」行者笑道：「煩星官也把我頭上摸摸。」星官道：「你未遭毒，摸他何為？」行者道：「昨日也曾遭過，只是過了夜，才不疼。如今還有些麻癢，只恐發天陰，也煩治治。」星官真個也把頭上摸了一摸，吹口氣，也就解了餘毒，不麻不癢了。八戒發狠道：「哥哥，去打那潑賤去。」星官道：「正是，正是。你兩個叫他出來，等我好降他。」那星官用手把嘴唇上摸了一摸，吹一口气，就不疼了。呆子欢喜下拜道：「妙啊！妙啊！」行者笑道：「烦星官也把我头上摸摸。」星官道：「你未遭毒，摸他何为？」行者道：「昨日也曾遭过，只是过了夜，才不疼。如今还有些麻痒，只恐发天阴，也烦治治。」星官真个也把头上摸了一摸，吹口气，也就解了余毒，不麻不痒了。八戒发狠道：「哥哥，去打那泼贱去。」星官道：「正是，正是。你两个叫他出来，等我好降他。」
逐句解 Line by line
The Star Officer passed his hand once over the lip and blew a breath upon it, and the pain was gone.
摸了一摸 is the verb-一-verb pattern of brief action; the 一 takes yì before the first tone of 摸.
The idiot bowed down in delight, saying, “Wonderful! Wonderful!”
妙啊！ carries its own terminal and is joined to the unit before it, being a bare exclamation on the same source line.
Pilgrim said with a laugh, “Might I trouble the Star Officer to pass his hand over my head as well?”
摸摸 is a verbal reduplication of casual aspect. No guarded graph falls in this segment.
The Star Officer said, “You did not take the poison. What would you be touched for?”
何為 takes 為 as the purposive wèi — for what purpose — against the copular wéi of 未為貴 and 真陽為至寶 elsewhere in the chapter.
Pilgrim said, “I did take it, yesterday. Only, a night having passed, it left off hurting.
曾遭過 marks completed past experience. The 不 stays bù before the second tone of 疼.
“There is still some numbness and itching in it, and I am afraid it may come on when the sky turns overcast. Physic that too, if you please.”
發天陰 draws on the common belief that an old wound aches when the weather is about to turn. It is an entirely mortal complaint, offered by a monkey who survived Laozi's brazier.
The Star Officer did indeed pass his hand once over the head as well and blow a breath, and the residue of the poison was dissolved, and there was neither numbness nor itching left.
解了餘毒 takes 解 as jiě. 真個也 — did indeed also — carries a faint note of indulgence on the narrator's part.
Bajie said savagely, “Brother — let us go and beat that vile creature.”
發狠 is to work oneself into a fury. 潑賤 is the same coarse abuse Bajie used before the first engagement.
The Star Officer said, “Just so, just so. You two call her out, and let me subdue her.”
好降他 takes 降 as xiáng, to subdue; pypinyin gives the jiàng of descending, which would be wrong. It is the third 降 in the chapter to need this correction.
Pilgrim asks to be treated for an injury he has already recovered from, and the Star Officer declines on exactly that ground: 你未遭毒，摸他何為 — you did not take the poison; what would you be touched for? It is a small, precise piece of characterization. Having watched his brother cured in a single gesture, Pilgrim wants the gesture too, and has to argue his way into it.
The argument he produces is the best joke in the passage because it is so thoroughly mortal. There is still some numbness and itching, he says, and he is afraid it may 發天陰 — come on when the sky turns overcast. This is the complaint of every old soldier and every rheumatic farmer: the wound that aches before rain. It is being made by a creature who ate the peaches of immortality, was beheaded repeatedly at the Palace of the Dipper and the Ox, and spent forty-nine days in an alchemical furnace without harm.
The officer humours him — 真個也把頭上摸了一摸, he did indeed pass his hand over the head as well — and the residue is dissolved. With that the party is whole again for the first time since the first engagement, and Bajie, who a moment ago was whimpering behind his hand, immediately proposes going back to fight. The chapter's long sequence of defeats ends here, and it ends not with a victory but with two minor injuries being tidied away.