結為兄弟 The King Pleads, the Monk Demurs
那國王聞言，急回頭，便請三藏道：「長老若有手段，放法力，捉了妖魔，救我孩兒回朝，也不須上西方拜佛，長髮留頭，朕與你結為兄弟，同坐龍床，共享富貴如何？」三藏慌忙啟上道：「貧僧粗知念佛，其實不會降妖。」國王道：「你既不會降妖，怎麼敢上西天拜佛？」那国王闻言，急回头，便请三藏道：「长老若有手段，放法力，捉了妖魔，救我孩儿回朝，也不须上西方拜佛，长发留头，朕与你结为兄弟，同坐龙床，共享富贵如何？」三藏慌忙启上道：「贫僧粗知念佛，其实不会降妖。」国王道：「你既不会降妖，怎么敢上西天拜佛？」
逐句解 Line by line
Hearing this, the king turned quickly about and entreated Tripitaka: 'Elder, if you have the skill — if you would loose your power to take the demon and bring my child back to the court — then you need not go west to worship the Buddha at all. Grow out your hair, keep a full head, and I shall bind myself to you as a sworn brother; we shall sit together upon the dragon-couch and share its riches. What say you?'
手段 = "skill, means"; 放法力 = "to loose [one's] magic power." 救我孩兒 (兒 = ér, the child-noun) = "rescue my child." 長髮留頭 (長 = zhǎng, "to grow") = "let the hair grow, keep a full head" — that is, leave the monastic life for the world; 結為兄弟 (為 = wéi) = "to become sworn brothers." The king's lavish offer measures the desperation of his grief.
Tripitaka hastily replied, 'This humble monk knows only, and roughly, how to recite the Buddha's name; in truth I have no skill to subdue demons.'
粗知念佛 = "to know, but crudely, the recitation of the Buddha['s name]"; 降妖 (降 = xiáng) = "to subdue demons." Tripitaka's disclaimer is literally true — the demon-fighting is his disciples' office, not his — but it will not spare him the king's importuning.
Said the king, 'If you cannot subdue demons, how did you dare set out for the Western Heaven to worship the Buddha?'
The king presses the plain contradiction, as he sees it, between the perils of the road and the monk's professed helplessness — forcing Tripitaka to reveal that he does not travel alone.
The king's offer is a small drama of temptation. In his desperation he holds out to Tripitaka everything a worldly heart might crave — sworn brotherhood with a king, a seat upon the dragon-couch, a share of royal wealth — and, most pointedly, release from the pilgrimage itself: "grow out your hair, keep a full head," abandon the shaven vocation and return to the pleasures of the world. The proposal, though born of grief rather than malice, sets the secular life in its most alluring form against the monk's austere errand, and Tripitaka's unmoved refusal quietly affirms where his commitment lies.
His demurral is also, characteristically, the literal truth: Tripitaka genuinely cannot subdue demons — that labor belongs to his disciples, and he himself "knows only, and roughly, how to recite the Buddha's name." But the king's blunt logic (how, then, dared he undertake so perilous a journey?) will not let the truth rest as a refusal; it drives the monk toward the disclosure he has been at pains to avoid, that he travels with two companions of a most alarming aspect.