捎書寄信 The Bargain of the Letter
唐僧道：「貧僧乃是差往西天取經者，不期閑步，誤撞在此。如今要拿住我兩個徒弟，一齊蒸吃哩。」那公主陪笑道：「長老寬心，你既是取經的，我救得你。那寶象國是你西方去的大路，你與我捎一封書兒去，拜上我那父母，我就教他饒了你罷。」三藏點頭道：「女菩薩，若還救得貧僧命，願做捎書寄信人。」唐僧道：「贫僧乃是差往西天取经者，不期闲步，误撞在此。如今要拿住我两个徒弟，一齐蒸吃哩。」那公主陪笑道：「长老宽心，你既是取经的，我救得你。那宝象国是你西方去的大路，你与我捎一封书儿去，拜上我那父母，我就教他饶了你罢。」三藏点头道：「女菩萨，若还救得贫僧命，愿做捎书寄信人。」
逐句解 Line by line
Tripitaka said, 'This poor monk is one dispatched to the Western Heaven to fetch the scriptures. Walking idly, I strayed and blundered in here unawares; and now he means to seize my two disciples and steam and devour us all together.'
差往 frames the journey as an official posting rather than a private pilgrimage: 差 is chāi, to be sent on a charge, the word for a government errand. 貧僧, "this poor monk," is Tripitaka's standard humble first person. And then he reports the ogre's catering plan — 一齊蒸吃, steamed and eaten all together — with the same flatness he might use for the weather. The sentence-final 哩 is the light particle li.
The princess said with a coaxing smile, 'Set your heart at ease, elder. Since you are a scripture-seeker, I can save you. That Land of Precious Images lies on your high road westward; carry a letter there for me, pay my respects to my father and mother, and I shall have him spare you.'
Watch the smile. 陪笑 is the ingratiating, deal-making smile, and it tells you a proposition is coming before she says a word of it. 救得你 uses 得 as the potential de — "am able to save you" — a different animal from the dé of 得會 in Tripitaka's lament a page back, which meant "manage to." She calls the letter a 書兒, with the little suffix 兒 (er) making it a note rather than a document — small, intimate, nothing to worry about. 教 in 就教他饒了你 is jiào, the causative: I shall make him let you go. This is the hinge the whole chapter turns on.
Tripitaka nodded and said, 'Bodhisattva-lady, if indeed you would save this poor monk's life, I am willing to be the bearer of your letter and the carrier of your word.'
若還, "if indeed," takes 還 as hái; 救得 is the potential de again. 捎書寄信人 — carrier-of-the-letter and sender-of-the-word — is built out of a matched pair of two-syllable verbs, 捎書 and 寄信, and it turns Tripitaka's new job into something like a title. He takes it out of pure desperation, and it will shortly require him to lie to a king — a scruple about 誑語, false speech, that he raises himself in the very next scene.
The bargain of the letter is the structural pivot of the whole chapter. In three speeches the princess converts a doomed captive into a diplomatic courier: her stratagem, flagged by that 陪笑, trades Tripitaka's life for the delivery of a message to her parents, and in doing so launches the embassy to the Land of Precious Images that will pull the two disciples into a foreign court, set a king weeping over a letter, and send everyone back to this cave under arms.
It is also quietly a moral scene. Tripitaka accepts the office of 捎書寄信 because he has no alternative, and the reader is meant to feel the squeeze: to keep faith with her at the Baoxiang court he will have to be less than honest about her demon children, and he flags his own objection to 誑語, false speech, almost the moment the letter is in his hand. The little diminutive 書兒 keeps the human size of the transaction in view even as the machinery starts to turn.