As long as a person is a creature, he is temporal, perishable and cannot endure; for every human being, as naturally created, is nothing but a suitable vessel in which a proper human being can first develop through constant divine cooperation.
When the outer vessel has attained the sufficient degree of formation, for which God has equipped the vessel more than abundantly with all necessary components and qualities, then He awakens or, rather, develops His uncreated eternal Spirit in the human heart; and this Spirit, according to the measure of His effect, is what Moses understands and wishes to be understood by the two great lights set at the firmament of heaven, as all the patriarchs and prophets have also understood it thus and never otherwise.
Only then is this eternal, uncreated light, fully alive forever at the heavenly firmament within the person, the fully true director of the true day within him, teaching the former vessel to reshape itself entirely into its eternally uncreated divine being and thus to make the whole person a true child of God.
But every created person has a living soul, which is indeed also a spirit, and has the necessary capacity to recognize good and true, and evil and false, to appropriate the good and true for itself and banish the evil and false from itself; yet despite this it is not an uncreated but a created spirit and as such can never by itself attain the state of being a child of God.
But when according to the law given to it, it has accepted the good and true in all the humility and modesty of its heart and of its free will implanted by God, then such a humble, modest and obedient will has, to speak quite tangibly, become a proper heavenly firmament, because it had formed itself precisely according to the heavenly element placed in the human soul, and is thus wholly suited to receive within itself the purely uncreated Divine.
The purely Divine, or the uncreated Spirit of God, who is placed eternally at such a heavenly firmament, is the second, smaller light, which is now, like the uncreated great light, set at that same heavenly firmament and reshaped by the uncreated light into a co-uncreated light, without losing anything of its natural character, but gaining infinitely much in a fully spiritually purified sense. For the human soul by itself could never, ever behold God in His purest spiritual being, and conversely the purest uncreated Spirit of God could never behold the natural, since for Him there is no material natural existence; but in the aforementioned full union of the purest Spirit with the soul, the soul can now through the new Spirit that has come to it behold God in His primordial spiritual, purest being, and the Spirit through the soul behold the natural.
This is what Moses says: that a great light should rule the day and the small light the night, and determine the signs, that is, in all wisdom the ground of all manifestation and all created things; likewise it should also determine the times, days and years, which means recognizing divine wisdom, love and grace in all phenomena!
But the stars Moses also mentions are the countless useful kinds of knowledge concerning all individual things; these individual kinds of knowledge naturally come from the one principal knowledge and are therefore placed at the same heavenly firmament as the two principal lights.
And look, this is finally the fourth day of creation that Moses mentions in his Genesis, which, as is readily understood, has arisen just like the previous three from the same evening and morning of the person.’