又驚又喜 The Household Fears The Worst
那家子又驚又喜道：「是幾位騰雲駕霧的羅漢歇在我家，就是發願齋僧的，也齋不著這等好人。」更不計較茶飯，愈加供養。又說：「這兩個行者只怕鬥出不好來，地覆天翻，作禍在那裡！」那家子又惊又喜道：「是几位腾云驾雾的罗汉歇在我家，就是发愿斋僧的，也斋不着这等好人。」更不计较茶饭，愈加供养。又说：「这两个行者只怕斗出不好来，地覆天翻，作祸在那里！」
逐句解 Line by line
The household, half startled and half delighted, said: "So it is several cloud-riding, mist-driving arhats who are lodging in our house! Even a man who had vowed to feed monks could never manage to feed such good people as these."
齋不著: this 著 is zháo, managing to do a thing — not the zhe that keeps an action running. Because zháo is a rising-tone syllable, the 不 in front of it stays bù rather than shifting to bú.
They haggled even less over tea and rice, and grew all the more lavish in their provision.
供養 takes gòng, the making of offerings, as one makes offerings to the Buddha — not the gōng of 供給, to supply. 更 is gèng, all the more.
They said further: "These two Pilgrims — we only fear they may fight their way to some bad end, turning earth over and heaven upside down, and wreak havoc goodness knows where!"
作禍在那裡: 那 here is nǎ, the vague "goodness knows where", not the pointing nà. It is a worry about consequences, not about a location.
The household's reaction is the chapter's most human moment and it turns on one phrase: 又驚又喜, frightened and delighted at once. They have worked out that their guests are not ordinary monks, and the discovery is an honour and a threat in the same breath. Their response to both halves is to bring more food.
The compliment they pay is fine peasant hyperbole — even a man under a vow to feed monks could never manage to feed guests of this quality. Read against the chapter it is also quietly ironic. The household cannot tell an arhat from a monkey-sprite either, and is lavishing its best on a party that currently contains an impostor.
Then the fear surfaces. 地覆天翻，作禍在那裡 is the ordinary person's view of what happens when powers of this size start fighting near one's house. The novel has spent nine passages on tribunals in Heaven; here it remembers that the quarrel is taking place in somebody's yard.