留個活的 Keep One Of Them Alive
還有一個老龍婆撤身就走，被八戒扯住，舉鈀才築，行者道：「且住，莫打死他，留個活的，好去國內見功。」遂將龍婆提出水面。还有一个老龙婆撤身就走，被八戒扯住，举钯才筑，行者道：「且住，莫打死他，留个活的，好去国内见功。」遂将龙婆提出水面。
逐句解 Line by line
There was still the old dragon dame; she turned to go, and Eight Rules caught hold of her and had the rake up to strike when Pilgrim said, "Hold. Do not beat her to death. Keep one alive, so we have something to show at the capital."
還 is hái, still or besides — the adverb — and not the huán of giving back that this graph has taken three times in the chapter. 的 holds de and 鈀 is pá. 一個 takes 一 at yí before the falling 個 gè.
And so they carried the dragon dame up out of the water.
將 is the disposal marker jiāng. Eight graphs, a short narrator's clause standing alone on grammar — the seventh of its kind in the chapter, and it lands on the same eight-graph mark that four quote-closing tails have landed on and been declined at.
The dragon dame lives because she is useful. Pilgrim's reason is stated without any decoration at all: keep one alive, so there is something to show at the capital. She is not spared out of pity but because a court expects a prisoner.
It is worth setting against the rest of the chapter. Her husband was killed on the bank, a son at his own father's funeral, a grandson chopped into pieces on the shore, and her daughter has just been struck down with a rake. She survives the destruction of her entire house on the grounds of administrative convenience.