Seeing him shut the door, Pilgrim thought to himself: "This old thief said just now that he had rinsed rice into the pot. Is that false or true? As the common saying goes: the Way converts the worthy, the Buddha converts the fool."

心中 has 中 as zhōng, within. The proverb is quoted inside ordinary prose, marked off by the edition's inner quotation marks and not set out as verse, so it stays prose. It sorts people by what will reach them: reason for the worthy, the Buddha's harder methods for the fool. Wukong has just decided which sort he is dealing with, and everything he does next follows from that.

Let Old Monkey go in and have a look."

看看, the verb said twice, makes it casual — just a look, just popping in. What follows is a burglary.

Fine Great Sage! He made the finger-sign, worked a spell of invisibility, walked straight into the kitchen and looked about — and sure enough the pot was steaming, with half a pot of dry-cooked rice in it.

好大聖, "fine Great Sage!", is the formula that announces a display of power, rather like a drum roll. 捻著訣 uses zhe for a continuing state, fingers held in the sign. 廚中 and 看處 take zhōng and chù. 乾飯 is rice cooked dry, as against gruel, and 乾 here reads gān, dry — not qián, the heaven-trigram, which is the same character's other life.

He shoved the alms bowl in and scooped it brim-full, then mounted his cloud and turned back — of which no more here.

掗 is to press or shove a thing into a space. 不題, "no more of this", is the storyteller dropping one thread to pick up another — the spoken equivalent of a scene change.