And God said,
Let the waters bring forth abundantly the moving creature that has life, and fowl that may fly above the earth in the open firmament of heaven.
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Basil the Great
After the creation of the lights, then the waters were filled with living creatures, so that this portion of the world also was adorned. The earth had received its ornamentation from its own plants. The heavens had received the flowers of stars and had been adorned with two great lights as if with the radiance of twin eyes. It remained for the waters, too, to be given their proper ornament. The command came. Immediately rivers were productive, and marshy lakes were fruitful of species proper and natural to each. The sea was astir with all kinds of swimming creatures, and not even the water that remained in the slime and ponds was idle or without its contribution in creation. For clearly frogs and mosquitoes and gnats were generated from them.