Genesis 1:16

Just as the sun and the moon are said to be the great lights in the firmament of heaven, so also are Christ and the church in us. But since God also placed stars in the firmament, let us see what are also stars in us, that is, in the heaven of our heart. Moses is a star in us, which shines and enlightens us by his acts. And so are Abraham, Isaac, Jacob, Isaiah, Jeremiah, Ezekiel, David, Daniel, and all to whom the Holy Scriptures testify that they pleased God. For just as "star differs from star in glory" so also each of the saints, according to his own greatness, sheds his light upon us.

To me, as I meditate and consider in my mind concerning the creation of this world in which we are kept enclosed, even such is the rapidity of that creation; as is contained in the book of Moses, which he wrote about its creation, and which is called Genesis. God produced that entire mass for the adornment of His majesty in six days; on the seventh to which He consecrated it . . . with a blessing. For this reason, therefore, because in the septenary number of days both heavenly and earthly things are ordered, in place of the beginning I will consider of this seventh day after the principle of all matters pertaining to the number of seven; and as far as I shall be able, I will endeavour to portray the day of the divine power to that consummation.

In the beginning God made the light, and divided it in the exact measure of twelve hours by day and by night, for this reason, doubtless, that day might bring over the night as an occasion of rest for men's labours; that, again, day might overcome, and thus that labour might be refreshed with this alternate change of rest, and that repose again might be tempered by the exercise of day. On the fourth day He made two lights in the heaven, the greater and the lesser, that the one might rule over the day, the other over the night, Genesis 1:16-17 — the lights of the sun and moon and He placed the rest of the stars in heaven, that they might shine upon the earth, and by their positions distinguish the seasons, and years, and months, and days, and hours.

Indeed Moses said, "God made the two great lights, the greater light to rule the day, and the lesser light to rule the night; and [ He made ] the stars." [ Gen1:16 ] Although all that was done before the fourth day was begun in the evening, the works on the fourth day were fashioned at dawn. Because the third day had been completed, in that it is said, "It was evening and it was morning; day three," God did not create the two lights in the evening lest night be changed into day and morning be given priority over evening.

Because the days followed the same order in which the first day was created, the night of the fourth day, like that of the other days, preceded its day. And if its evening preceded its dawn, the lights were not created in the evening, but rather at dawn. But to say that one of them was created in the evening and the other at dawn cannot be allowed for Moses said, "Let there be lights," and "God made the two great lights." If they were great when they were created and they were created at dawn, then the sun would have stood in the east and the moon opposite it in the west. The sun would have been set very low because it was created in the place where it set out over the earth, whereas the moon would have been set higher because it was created in the place where it stands on the fifteenth day. Indeed, at the moment the sun appears over the earth, the lights see each other and then the moon sinks. From the position of the moon, from its size and from the light it produced, it is clear, then, that it was fifteen days old when it was created.

Just as the trees, the vegetation, the beasts, the birds and even mankind were old, so were they also young. They were old according to the appearance of their limbs and their substances, yet they were young because of the hour and moment of their creation. Likewise, the moon was both old and young. It was young, for it was but a moment old, but was also old, for it was full as it is on the fifteenth day.

If the moon had been created a day old or even two, it would have given no light; because of its proximity to the sun, it would not even have been visible. If it had been created about four days old, although it might have been visible, it would still not have given any light. This would have rendered false the verse "God created the two great lights," as well as "He said, 'Let there be lights in heaven to give light upon the earth.'" Therefore, the moon had to be fifteen days old. The sun, although it was only one day old, was nevertheless four days old, for it is according to the sun that each day was counted and will be reckoned. Accordingly, those eleven days that were added to the moon at that first moment, by which the moon was older than the sun, are also added to it each year, for these [ days ] are used in the lunar reckoning.

There was nothing lacking in that year for Adam and his descendants, for any deficiency in the measure of the moon had been filled in when the moon was created. Thus, Adam and his descendants learned from this year that, henceforth, eleven days were to be added to every year. Clearly then, it was not the Chaldeans who arranged the times and years; these things had been arranged before [ the creation of ] Adam.

9. The word great, if, for example we say it of the heaven of the earth or of the sea, may have an absolute sense; but ordinarily it has only a relative meaning, as a great horse, or a great ox. It is not that these animals are of an immoderate size, but that in comparison with their like they deserve the title of great. What idea shall we ourselves form here of greatness? Shall it be the idea that we have of it in the ant and in all the little creatures of nature, which we call great in comparison with those like themselves, and to show their superiority over them? Or shall we predicate greatness of the luminaries, as of the natural greatness inherent in them? As for me, I think so. If the sun and moon are great, it is not in comparison with the smaller stars, but because they have such a circumference that the splendour which they diffuse lights up the heavens and the air, embracing at the same time earth and sea. In whatever part of heaven they may be, whether rising, or setting, or in mid heaven, they appear always the same in the eyes of men, a manifest proof of their prodigious size. For the whole extent of heaven cannot make them appear greater in one place and smaller in another. Objects which we see afar off appear dwarfed to our eyes, and in measure as they approach us we can form a juster idea of their size. But there is no one who can be nearer or more distant from the sun. All the inhabitants of the earth see it at the same distance. Indians and Britons see it of the same size. The people of the East do not see it decrease in magnitude when it sets; those of the West do not find it smaller when it rises. If it is in the middle of the heavens it does not vary in either aspect. Do not be deceived by mere appearance, and because it looks a cubit's breadth, imagine it to be no bigger. At a very great distance objects always lose size in our eyes; sight, not being able to clear the intermediary space, is as it were exhausted in the middle of its course, and only a small part of it reaches the visible object. Our power of sight is small and makes all we see seem small, affecting what it sees by its own condition. Thus, then, if sight is mistaken its testimony is fallible. Recall your own impressions and you will find in yourself the proof of my words. If you have ever from the top of a high mountain looked at a large and level plain, how big did the yokes of oxen appear to you? How big were the ploughmen themselves? Did they not look like ants? If from the top of a commanding rock, looking over the wide sea, you cast your eyes over the vast extent how big did the greatest islands appear to you? How large did one of those barks of great tonnage, which unfurl their white sails to the blue sea, appear to you. Did it not look smaller than a dove? It is because sight, as I have just told you, loses itself in the air, becomes weak and cannot seize with exactness the object which it sees. And further: your sight shows you high mountains intersected by valleys as rounded and smooth, because it reaches only to the salient parts, and is not able, on account of its weakness, to penetrate into the valleys which separate them. It does not even preserve the form of objects, and thinks that all square towers are round. Thus all proves that at a great distance sight only presents to us obscure and confused objects. The luminary is then great, according to the witness of Scripture, and infinitely greater than it appears.
10. See again another evident proof of its greatness. Although the heaven may be full of stars without number, the light contributed by them all could not disperse the gloom of night. The sun alone, from the time that it appeared on the horizon, while it was still expected and had not yet risen completely above the earth, dispersed the darkness, outshone the stars, dissolved and diffused the air, which was hitherto thick and condensed over our heads, and produced thus the morning breeze and the dew which in fine weather streams over the earth. Could the earth with such a wide extent be lighted up entirely in one moment if an immense disc were not pouring forth its light over it? Recognise here the wisdom of the Artificer. See how He made the heat of the sun proportionate to this distance. Its heat is so regulated that it neither consumes the earth by excess, nor lets it grow cold and sterile by defect.
To all this the properties of the moon are near akin; she, too, has an immense body, whose splendour only yields to that of the sun. Our eyes, however, do not always see her in her full size. Now she presents a perfectly rounded disc, now when diminished and lessened she shows a deficiency on one side. When waxing she is shadowed on one side, and when she is waning another side is hidden. Now it is not without a secret reason of the divine Maker of the universe, that the moon appears from time to time under such different forms. It presents a striking example of our nature. Nothing is stable in man; here from nothingness he raises himself to perfection; there after having hasted to put forth his strength to attain his full greatness he suddenly is subject to gradual deterioration, and is destroyed by diminution. Thus, the sight of the moon, making us think of the rapid vicissitudes of human things, ought to teach us not to pride ourselves on the good things of this life, and not to glory in our power, not to be carried away by uncertain riches, to despise our flesh which is subject to change, and to take care of the soul, for its good is unmoved. If you cannot behold without sadness the moon losing its splendour by gradual and imperceptible decrease, how much more distressed should you be at the sight of a soul, who, after having possessed virtue, loses its beauty by neglect, and does not remain constant to its affections, but is agitated and constantly changes because its purposes are unstable. What Scripture says is very true, As for a fool he changes as the moon. Sirach 27:11
I believe also that the variations of the moon do not take place without exerting great influence upon the organization of animals and of all living things. This is because bodies are differently disposed at its waxing and waning. When she wanes they lose their density and become void. When she waxes and is approaching her fullness they appear to fill themselves at the same time with her, thanks to an imperceptible moisture that she emits mixed with heat, which penetrates everywhere. For proof, see how those who sleep under the moon feel abundant moisture filling their heads; see how fresh meat is quickly turned under the action of the moon; see the brain of animals, the moistest part of marine animals, the pith of trees. Evidently the moon must be, as Scripture says, of enormous size and power to make all nature thus participate in her changes.
11. On its variations depends also the condition of the air, as is proved by sudden disturbances which often come after the new moon, in the midst of a calm and of a stillness in the winds, to agitate the clouds and to hurl them against each other; as the flux and reflux in straits, and the ebb and flow of the ocean prove, so that those who live on its shores see it regularly following the revolutions of the moon. The waters of straits approach and retreat from one shore to the other during the different phases of the moon; but, when she is new, they have not an instant of rest, and move in perpetual swaying to and fro, until the moon, reappearing, regulates their reflux. As to the Western sea, we see it in its ebb and flow now return into its bed, and now overflow, as the moon draws it back by her respiration and then, by her expiration, urges it to its own boundaries.
I have entered into these details, to show you the grandeur of the luminaries, and to make you see that, in the inspired words, there is not one idle syllable. And yet my sermon has scarcely touched on any important point; there are many other discoveries about the size and distance of the sun and moon to which any one who will make a serious study of their action and of their characteristics may arrive by the aid of reason. Let me then ingenuously make an avowal of my weakness, for fear that you should measure the mighty works of the Creator by my words. The little that I have said ought the rather to make you conjecture the marvels on which I have omitted to dwell. We must not then measure the moon with the eye, but with the reason. Reason, for the discovery of truth, is much surer than the eye.
Everywhere ridiculous old women's tales, imagined in the delirium of drunkenness, have been circulated; such as that enchantments can remove the moon from its place and make it descend to the earth. How could a magician's charm shake that of which the Most High has laid the foundations? And if once torn out what place could hold it?
Do you wish from slight indications to have a proof of the moon's size? All the towns in the world, however distant from each other, equally receive the light from the moon in those streets that are turned towards its rising. If she did not look on all face to face, those only would be entirely lighted up which were exactly opposite; as to those beyond the extremities of her disc, they would only receive diverted and oblique rays. It is this effect which the light of lamps produces in houses; if a lamp is surrounded by several persons, only the shadow of the person who is directly opposite to it is cast in a straight line, the others follow inclined lines on each side. In the same way, if the body of the moon were not of an immense and prodigious size she could not extend herself alike to all. In reality, when the moon rises in the equinoctial regions, all equally enjoy her light, both those who inhabit the icy zone, under the revolutions of the Bear, and those who dwell in the extreme south in the neighbourhood of the torrid zone. She gives us an idea of her size by appearing to be face to face with all people. Who then can deny the immensity of a body which divides itself equally over such a wide extent?
But enough on the greatness of the sun and moon. May He Who has given us intelligence to recognise in the smallest objects of creation the great wisdom of the Contriver make us find in great bodies a still higher idea of their Creator. However, compared with their Author, the sun and moon are but a fly and an ant. The whole universe cannot give us a right idea of the greatness of God; and it is only by signs, weak and slight in themselves, often by the help of the smallest insects and of the least plants, that we raise ourselves to Him. Content with these words let us offer our thanks, I to Him who has given me the ministry of the Word, you to Him who feeds you with spiritual food; Who, even at this moment, makes you find in my weak voice the strength of barley bread. May He feed you for ever, and in proportion to your faith grant you the manifestation of the Spirit in Jesus Christ our Lord, to whom be glory and power for ever and ever. Amen.

The Manichaeans ask how it could be that the heavenly bodies, that is, the sun and the moon and the stars, were made on the fourth day. How could the three previous days have passed without the sun? For we now see that a day passes with the rising and setting of the sun, while night comes to us in the sun's absence when it returns to east from the other side of the world. We answer them that the previous three days could each have been calculated by as great a period of time as that through which the sun passes, from when it rises in the east until it returns again to the east.… This would be our answer if we were not held back by the words "and evening came and morning came," for we see that this cannot now take place without the movement of the sun. Hence we are left with the interpretation that in that period of time the divisions between the works were called evening because of the completion of the work that was done and morning because of the beginning of the work to come. Scripture says this after the likeness of human works, since they generally begin in the morning and end at evening.… [Then Scripture says, "And God set them in the firmament of the heavens to give light upon the earth, to rule over the day and over the night, and to divide the light from the darkness."] Again they ask, "How did God previously divide the light and the darkness if he made the heavenly bodies on this the fourth day?" Therefore these words, "to divide the light from the darkness," mean "to divide among themselves the light and the darkness, so that the day is given to the sun and the night to the moon and the other stars." The day and the night had already been distinguished but not yet in relation to the heavenly bodies.

God also made two great luminaries. We can understand the great luminaries not so much by comparison with others but by their role, as the heaven is great and the sea is great. For there is also the great sun which fills the world with its heat, or the moon with its light, which, wherever they are in the sky, illuminate all the earth and are equally observed by everyone. An evident example of their greatness is that they appear the same to all people. For if they appeared smaller to those far away and larger to those nearer, it would indicate a limitation of their size.

The greater light to rule the day, and the lesser light to rule the night, and the stars; and He set them in the firmament of the heaven. The greater light is the sun, not only in its form whatever it may be, but also in the magnitude of its light, by which it is believed to illuminate both the lesser light and the stars. It is also greater in the power of its heat, which warms the world when it rises, whereas the previous days before its creation had no heat at all: but the fact that the moon is seen as of equal size to the sun is said to be because the sun is much farther from the earth and higher than the moon; therefore, its true size cannot be discerned by us who dwell on the earth. For all things set farther away generally appear smaller.

And he said, "And the lesser light to rule the night, and the stars; and he set them in the firmament of the heaven"; because although it happens sometimes that the moon and the major stars are seen in the day every month, it is certain that they bring some aid of light not to the day but only to the night.

two great lights: As Chrysostom says, the two lights are called great, not so much with regard to their dimensions as to their influence and power. For though the stars be of greater bulk than the moon, yet the influence of the moon is more perceptible to the senses in this lower world. Moreover, as far as the senses are concerned, its apparent size is greater.
In the words of Basil (Hom. v in Hexaem.), plants were recorded as produced before the sun and moon, to prevent idolatry, since those who believe the heavenly bodies to be gods, hold that plants originate primarily from these bodies. Although as Chrysostom remarks (Hom. vi in Gen.), the sun, moon, and stars cooperate in the work of production by their movements, as the husbandman cooperates by his labor.