fire symbolism of the mystic quadriga

There is a distinct fire symbolism in the mystic quadriga mentioned by Dio Chrysostom:

(a)

The highest god always drives his chariot round in a circle. The chariot is drawn by four horses, and the outside horse moves very quickly. He has a shining coat, bearing on it the sign of the zodiac and the constellations

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(b)

The second horse goes more slowly and is illuminated on one side only

CW5 ¶ 423
(c)

The third horse is slower still, and the fourth horse runs round himself

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(d)

Once, however, the outside horse set the mane of the second horse on fire with his fiery breath, and the third horse drenched the fourth with streams of sweat

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(e)

Then the horses dissolve and merge with the substance of the strongest and most fiery, which now becomes the charioteer

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(f)

The horses represent the four elements. The catastrophe signifies world conflagration and the deluge, after which the division of God into Many ceases, and the divine One is restored

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(g)

There can be no doubt that the quadriga is meant as an astronomical symbol of Time

CW5 ¶ 423