Ah!

The storyteller's third interjection in the chapter, and this one is triumph.

This is exactly it:

Three characters and a colon, and the closing verse follows.

The Dharma King destroys the Dharma, and the Dharma is without end; the Dharma runs through heaven and earth, and the Great Way goes through.

Four instances of one character in fourteen, which is the whole trick of these two lines. 法 carries three senses at once and the line uses all three: the Buddha's teaching, which is what the Sanskrit dharma names; plain law, the king's kind; and a method or a magic art, which is Pilgrim's kind. 乾坤 is heaven and earth, the pair of hexagrams that open the Book of Changes, and the first character keeps its qián reading in that fixed compound rather than the gān of dryness.

The ten thousand teachings come back at root to one body; the wondrous marks of the Three Vehicles were the same from the first.

乘 is shèng in 三乘, the Three Vehicles — the three paths of Buddhist practice, and the reading for a vehicle in that sense is never the chéng of riding. 相 is xiàng, an appearance or a mark, the standard rendering of the Sanskrit lakṣaṇa, not the xiāng that means mutually.