When seventy years are
fulfilled for Babylonia. This would take us to the 520s, about a decade
after the destruction of the Babylonian empire by Persia. But the number of
seventy is clearly formulaic, a way of indicating that the return to Zion will
not occur for some three generations. In the Book of Daniel, this prophecy will
be given a novel interpretation in which seventy is understood to be seventy
units of seven years, thus bringing it more or less to the time when Daniel was
written. (Robert Alter, The Hebrew Bible, 3 vols. [New York: W. W.
Norton & Company, 2019], 2:955)
