A fine fire it was:

好火 — "a fine fire" — is the same formulaic cue as 好殺 earlier, handing the narrative over to a descriptive set-piece.

That fire was not the fire of heaven, nor the fire of a furnace, nor was it the fire of a hilltop, nor the fire beneath a stove; it was the one spark of numinous light drawn forth of itself from the Five Phases.

The verse opens by ruling out every ordinary fire the reader might picture — not heaven's fire, not a furnace, not a hilltop blaze, not the fire under a stove — before naming what it is: 一點靈光火, a single spark of spirit-fire, drawn 五行中 (wǔ xíng zhōng), from inside the Five Phases themselves, with 行 read xíng. The stacked denials are the point: this fire is not a bigger version of a known thing, it is a different kind of thing.

This fan, too, was no thing common in the mortal world, nor a thing wrought by human craft; it was a true treasure, grown into being ever since chaos was first cleft open.

The same structure is then applied to the fan. 凡間 is "the mortal world," 間 read jiān; 自開闢混沌以來, "ever since the parting of chaos," sets the fan among the things that were there before there was anything.

Use this fan to fan this fire, and it dazzles and blazes, like lightning flashing through red silk;

煌煌燁燁 is "glittering, blazing," two doubled words in a row. 電掣紅綃 is "lightning across red gauze" — light shot through a thin bright fabric.

glowing and glittering, it is like rosy cloud flying over crimson damask.

灼灼輝輝 is "gleaming, radiant"; 卻似 (què sì) is "yet like," 似 read sì. The couplet doubles the one before it, piling brightness on brightness in the way this kind of verse likes to.

Not a single wisp of blue smoke more — all is red flame filling the hills.

更無 is "not even, still less," 更 read gèng; 盡是 is "all is." The detail that there is no smoke at all is not decoration — smokeless burning is what marks the fire as unearthly.

It burned till the pines on the ridge turned to trees of fire, and the cypress before the cliff became lanterns.

燒得 is "burned until," 得 the degree complement de. Pines turn into trees of fire and cypresses into lanterns: the transformations measure the completeness of the blaze better than any statement of scale could.

The beasts in that den, grudging their lives, went dashing west and east;

那窩中 is "in that den," 那 pointing (nà) and 中 read zhōng. The verse turns to the fleeing animals, which is how it takes the fire's measure.

the birds in this wood, cherishing their feathers, flew high and far away.

惜羽毛 is "sparing their plumage." Set against the beasts of the line before, it completes a picture of a forest emptied by flame — and the pairing of grudged lives against cherished feathers is a small joke at the birds' expense.

This tract of divine fire went floating and scorching through the air, burning till the stones split and the streams ran dry and the whole ground turned red.

石爛溪乾 — "stones melt, streams run dry," with 乾 read gān, dry, not the qián of the heaven-trigram met a few passages back. The verse ends on total devastation.