虎現原形 The Headless Tiger
卻說那道士連叫三聲，人頭不到，怎似行者的手段，長不出來，腔子中，骨都都紅光迸出。可憐空有喚雨呼風法，怎比長生果正仙。須臾，倒在塵埃。眾人觀看，乃是一隻無頭的黃毛虎。却说那道士连叫三声，人头不到，怎似行者的手段，长不出来，腔子中，骨都都红光迸出。可怜空有唤雨呼风法，怎比长生果正仙。须臾，倒在尘埃。众人观看，乃是一只无头的黄毛虎。
逐句解 Line by line
Now that Daoist called out three times over, but the head did not come; how could he match the Pilgrim's arts? — it would not grow out, and from the neck-cavity, with a gushing gu-du-du, a red light burst forth.
Three calls, and nothing comes. 怎似行者的手段 — how could he match the Pilgrim's arts? (似 = sì.) Then, instead of blood, 紅光迸出, a burst of red light out of the neck: the life-force of a false immortal draining off in one gush. 骨都都 is the sound of it, a glugging rush, and in a sound-word like this the 都 is dū, not the dōu that means "all." 長不出來: 長 = zhǎng. 那 = nà; 子 = zi; 中 = zhōng.
Pity — vainly he held the art of summoning rain and calling wind; how should it match the true immortal's fruit of long life?
The narrator drops into a matched pair of lines to name the moral, and one character carries it: 長生 is cháng, long life, everlasting — not the zhǎng of growing that has run through every line of this ordeal. He could not grow a head because he never had the eternity that would have let him. 空有喚雨呼風法 — the rain-and-wind sorcery was real, and empty.
In a moment, he fell down in the dust.
倒在塵埃: 倒 is dǎo again here, to fall — the toppling sound, not the dào of "on the contrary" from two passages back. He goes down in the dust.
The crowd looked, and it was a single headless, yellow-furred tiger.
眾人觀看: 觀 = guān, to look — not the guàn that names a Daoist abbey, which is the reading this chapter's setting might tempt you toward. And what the crowd sees is 一隻無頭的黃毛虎, a headless yellow-furred tiger: the beast that has been wearing the robe for twenty years.
Three calls and the head does not come. Instead of blood there is 紅光迸出, a burst of red light out of the neck with a glugging rush the storyteller writes as 骨都都 — the drained life-force of a false immortal going all at once. He falls, and what the crowd gathers round is 一隻無頭的黃毛虎, a headless yellow-furred tiger. The animal-reveal is one of this novel's standing devices, and here it carries the full weight of the chapter's argument.
The matched pair of lines run into the narrative states that argument outright — 空有喚雨呼風法，怎比長生果正仙 — and the case rests on one character read two ways. Through every line of this ordeal 長 has been zhǎng, to grow: grow a head, grow the belly shut, grow whole. Here it is cháng, in 長生, long life. The beast could not grow a head because he never possessed the eternity that would have let him. His rain-and-wind sorcery was genuine, and it was empty.