Genesis 1:8
And God called the firmament Heaven. And the evening and the morning were the second day.
And God called the firmament heaven,.... Including the starry and airy heavens: it has its name from its height in the Arabic language, it being above the earth, and reaching to the third heaven; though others take the word "shamaim" to be a compound of two words, "sham" and "maim", that is, there are waters, namely, in the clouds of heaven:
And the evening; and the morning were the second day; these together made up the space of twenty four hours, which was another natural day; the body of light, created on the first day, having again moved round the chaos in that space of time; or else the chaos had turned round on its own axis in that time, which revolution produced a second day; and which, according to Capellus, was the nineteenth of April, and according to Bishop Usher the twenty fourth of October. It is an observation that everyone may make, that the phrase,
and God saw that it was good, is not used at the close of this day's work, as of the rest: the reason some Jewish writers give is, because the angels fell on this day; but it is a much better which Jarchi gives, and that is, because the work of the waters was not finished; it was begun on the second day, and perfected on the third {d}; and therefore the phrase is twice used in the account of the third day's work: the Septuagint version adds it here indeed, but without any foundation.
{d} Vid. Maimon. Moreh Nevochim, par. 2. c. 30.