V. 6-8. And God said, Let there be a firmament between the waters; and let it be a difference between the waters. Then God made the stronghold and separated the water under the stronghold from the water above the stronghold. And it came to pass thus. And God called the firmament Heaven. Then the evening and the morning became the other day.
(19) Here we must always be careful to remain in the simple mind. Therefore, just as on the first day he made a desolate and empty earth, and the sky with a dark mist or dark waters, so here especially on the second day he took the sky before him and made a firmament; that is, the raw, dark waters, which before were nothing but a floating and weaving thing, he made firm here, and made it so that he set the firmament between two waters. For before there were waters all around the earth. But now he reached into the midst of them, and divided the waters into two parts, keeping one above and the other below. In the midst of it he makes a ring, which we call heaven, and calls it a firmament, so that it does not waver and move to and fro, and is inconstant, like the air and the water, and like it was in the beginning, but stands firm, and goes in a straight course, and yet has under it the air, the water and the sea. But before that, before he was thus made ready, he also went unstable.
(20) But what kind of water is above the stronghold, we cannot well know. Therefore, as I have said [ยง15], we must give room to the Holy Spirit and say that he knows better than we understand. In this way, God can certainly preserve the water above the sky. I wanted to make the air out of the water above the firmament, but it still remains under heaven forever. Therefore we must be captive, and remain that the heaven is made in the midst of the waters.
21. there we have now, as he did for the first time
He takes away the inanimate nature of heaven and gives it a secure nature, so that it is properly prepared and placed in the two forms, so that the darkness and floating disappear, that is, that it is no longer dark on the deep, and the wind no longer floats on the water. And when it is thus prepared, only on the next day does God give it its proper name and call it heaven. On the first day it was heaven and earth, but it did not yet have a proper name. For it was not yet completely prepared and fixed, so that it could be called.
So we have, I think, the most simple and right understanding of the text. But we do not want to set a goal for the Holy Spirit. If he gives us a better one, then we also want to have it gladly. So Moses now decides that again evening and morning have become the other day. So he has made over this work also a day and night.
(23) But here a question arises: Why does Moses not add, "God saw it good," and take away the blessing, and not write that God was pleased with it, since he remembers it all the other days? People were also very concerned about what he meant by this and thought about it in many ways. But I think it remains well hidden. That is why I do not know how to explain it. They say that the second number is a division out of unity, which 2) means love; as the same number in Scripture has a great sacrament and secrecy. But we will leave that aside. Be it as it may, there is no doubt that Moses did not forget to add it, but it was done out of deliberate counsel. So now heaven is prepared, that it is no longer dark, nor shaky, nor wavering, but stands firm, and has its space and place. Follow