裡面乾淨 Tie Him Up and Starve Him Clean
老怪道:「先鋒,憑你有何高見?」先鋒道:「依著我,把唐僧送在後園,綁在樹上,兩三日不要與他飯吃:一則圖他裡面乾淨;老怪道:「先锋,凭你有何高见?」先锋道:「依着我,把唐僧送在后园,绑在树上,两三日不要与他饭吃:一则图他里面干净;
逐句解 Line by line
The old fiend said, "Vanguard, what better notion have you?"
高見 — your lofty view — is a courtesy for another person's opinion, and the commander is now formally consulting the imp he promoted an hour ago. He has stopped having plans and started commissioning them.
The vanguard said, "Do as I say. Put the Tang Monk in the back garden, tie him to a tree, and give him nothing to eat for two or three days. For one thing, it makes him clean inside;
著 is zhe in 依著我, going along with me. 乾 is gān in 乾淨, clean — and clean here means emptied out, the way an animal is starved before slaughter. It is the same word the master will use in a moment about dying, in a completely different sense.
The plan is to starve him for two or three days, and the reason given first is hygiene. The novel lets a demon apply ordinary butchery practice to a man without comment.
That word for clean is about to do a great deal of work. Tripitaka will use it four times in the next scene about his own death, and never once about his digestion.