Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 10

Chapter 10.—Of the Different Computation of the Ages of the Antediluvians, Given by the Hebrew Manuscripts and by Our Own. 803

Wherefore, although there is a discrepancy for which I cannot account between our manuscripts and the Hebrew, in the very number of years assigned to the antediluvians, yet the discrepancy is not so great that they do not agree about their longevity.  For the very first man, Adam, before he begot his son Seth, is in our manuscripts found to have lived 230 years, but in the Hebrew mss. 130.  But after he begot Seth, our copies read that he lived 700 years, while the Hebrew give 800.  And thus, when the two periods are taken together, the sum agrees.  And so throughout the succeeding generations, the period before the father begets a son is always made shorter by 100 years in the Hebrew, but the period after his son is begotten is longer by 100 years in the Hebrew than in our copies.  And thus, taking the two periods together, the result is the same in both.  And in the sixth generation there is no discrepancy at all.  In the seventh, however, of which Enoch is the representative, who is recorded to have been translated without death because he pleased God, there is the same discrepancy as in the first five generations, 100 years more being ascribed to him by our mss. before he begat a son.  But still the result agrees; for according to both documents he lived before he was translated 365 years.  In the eighth generation the discrepancy is less than in the others, and of a different kind.  For Methuselah, whom Enoch begat, lived, before he begat his successor, not 100 years less, but 100 years more, according to the Hebrew reading; and in our p. 292 mss. again these years are added to the period after he begat his son; so that in this case also the sum-total is the same.  And it is only in the ninth generation, that is, in the age of Lamech, Methuselah’s son and Noah’s father, that there is a discrepancy in the sum total; and even in this case it is slight.  For the Hebrew mss. represent him as living twenty-four years more than ours assign to him.  For before he begat his son, who was called Noah, six years fewer are given to him by the Hebrew mss. than by ours; but after he begat this son, they give him thirty years more than ours; so that, deducting the former six, there remains, as we said, a surplus of twenty-four.

Footnotes

Our own Mss., of which Augustin here speaks, were the Latin versions of the Septuagint used by the Church before Jerome’s was received; the “Hebrew Mss.” were the versions made from the Hebrew text.  Compare De Doct. Christ. ii. 15 et seqq.