原文 Original text
繁體 Traditional
Reader's edition
戴不得巾兒 Too Big for a Headcloth
八戒的頭大，戴不得巾兒，被行者取了些針線，把頭巾扯開兩頂，縫做一頂，與他搭在頭上；揀件寬大的衣服，與他穿了。八戒的头大，戴不得巾儿，被行者取了些针线，把头巾扯开两顶，缝做一顶，与他搭在头上；拣件宽大的衣服，与他穿了。
逐句解 Line by line
八戒的頭大，戴不得巾兒，被行者取了些針線，把頭巾扯開兩頂，縫做一頂，與他搭在頭上；
八戒的头大，戴不得巾儿，被行者取了些针线，把头巾扯开两顶，缝做一顶，与他搭在头上；
Bajie's head was too big to take a headcloth, so Pilgrim fetched needle and thread, tore two of them open, sewed them into one, and draped it over him;
Bajie asked five passages back how a headcloth was supposed to sit on a shaved head, and here is the answer, in needle and thread. 得 sits between a verb and its negative here and reads de: 戴不得 is cannot be worn. Notice who is doing the tailoring — the Great Sage, with a needle.
揀件寬大的衣服，與他穿了。
拣件宽大的衣服，与他穿了。
and picked out a roomy coat and put that on him too.
揀 is to pick out from among several, which tells you the haul from the inn was large enough to choose from.
The pig's head is a running problem in the novel and it is usually a joke. Here it is a logistical constraint solved with two headcloths and a needle, and the solution is described with the precision of someone who has actually done it.
It is also the answer to the objection Bajie raised, which the chapter has not forgotten. He said a headcloth would not sit on a head like his; he was right; Pilgrim made a bigger headcloth.