一把摟住 What Sutra Are You Chanting
行者口裡嗚哩嗚喇，只情念經。那女子走近前，一把摟住道：「小長老，念的甚麼經？」行者道：「許下的。」行者口里呜哩呜喇，只情念经。那女子走近前，一把搂住道：「小长老，念的甚么经？」行者道：「许下的。」
逐句解 Line by line
Pilgrim mumbled and droned away in his throat, keeping steadily at his recitation.
嗚哩嗚喇 is pure sound — the noise of someone reciting without articulating, which is what chanting actually sounds like from across a room.
The woman came up close, put her arms about him and said, "Little elder, what sutra is it you are chanting?"
長 is zhǎng in the word for elder, seniority — and calling a boy of twelve a little elder is the ordinary courtesy for any monk, however young. 甚 is shén, the question word.
Pilgrim said, "One I promised."
許下的, promised, means a recitation vowed to a deity in exchange for something — a standard piece of Chinese religious practice, and a perfectly ordinary thing for a novice to be doing at night.
The trap closes and neither party shows a card. She takes hold of a boy she means to kill; he answers her with three characters about a vow and keeps tapping the wooden fish.
His answer is very well chosen. A promised recitation is exactly the kind of duty that would keep a young monk up alone at night, and it explains his presence without inviting a question. He has thought about his cover story.
The mumbling is the detail that sells it. He is not performing piety at her; he is droning, the way a bored child does, which is precisely what the fiend has come looking for.