Day 4 luminaries in heaven for light upon the earth
The work of the fourth day is the production of luminaries in heaven — sun, moon, and other stars — to carry light upon the earth. Moses narrates that the earth germinated before the sun and stars were made, because he first teaches which substances God made. The sun was therefore made the executor, not the institutor, of nature, and fittingly on the fourth day, as Moses teaches in Genesis 1:14 and following.
Moses speaks of the stars with respect to us to whom he was giving the law. For they can be considered, Aquinas testifies, either according to their own act, or with respect to God whom they serve, or with respect to us for whom they are useful — whence Deuteronomy warns us not to adore the sun, moon, and stars which were made for our ministry. When Moses says God made the greater and lesser luminary — the SUN and the MOON — he speaks to humans of our system, for whom to sense the moon is the second luminary presiding over the night. And he explains the use of the luminaries: that they make all things manifest by illuminating; that they distinguish day and night; that they are for seasons, days, and years.
We also condemn here the Muhammadan delirium that the moon was made by God equally bright as the sun, but that the angel Gabriel, flying by chance, extinguished it by the wind of his wings. What is more foolish than that so great a work of God could be extinguished by an angel by chance, and was not so made from God's intention for the utility of the earth and other causes?
Latin
Opus quarti diei est productio luminarium in caelo — solis, lunae aliorumque siderum — ad lucem super terram deferendam. Terram prius germinasse quam fieret sol et stellae narrat Moses, quia quae a Deo factae sint substantiae primitus docet. Sol igitur factus est exsecutor, non institutor naturae, et convenienter in quarto die, ut docet Moses Gen. I.14 seqq. Porro Moses de stellis loquitur respectu nostri quibus legem dabat. Possunt enim, teste Aquinate, considerari vel secundum proprium actum, vel respectu Dei cui serviunt, vel respectu nostri quibus sunt utiles — unde in Deuteronomio monet ne adoremus solem lunam et stellas quae factae sunt nobis in ministerium. Cum Moses dicit Deum fecisse luminare majus et minus — SOLEM et LUNAM — loquitur ad homines nostri systematis, quibus ad sensum luna est luminare secundum praesidens nocti. Et explicat Moses usum luminarium: quod manifestent omnia illuminando; quod distinguant diem ac noctem; quod sint in tempora, dies et annos. Damnamus etiam hic Mahumedicum delirium, quod luna facta sit a Deo aeque lucida ac sol sed angelus Gabriel casu volans eam vento alarum suarum extinxerit. Quid stultius quam opus Dei tantum casu ab angelo posse extingui, et non ita factum ex Dei intentione propter terrae utilitatem aliasque causas?