The hint is of the fertilizing action of the warm light on the seed hidden in the soil.

See _The Names of the Gods in the Kiche Myths, Trans.

of the Amer.Phil.

Soc._ 1881.] Now began the struggle between the two brothers, Tezcatlipoca and Quetzalcoatl, which was destined to destroy time after time the world, with all its inhabitants, and to plunge even the heavenly luminaries into a common ruin.
The half sun created by Quetzalcoatl lighted the world but poorly, and the four gods came together to consult about adding another half to it.

Not waiting for their decision, Tezcatlipoca transformed himself into a sun, whereupon the other gods filled the world with great giants, who could tear up trees with their hands.