An alternative and probably more reasonable resolution relates to the authorship of Daniel. Nowhere does Jeremiah state that Jerusalem was to be devastated for seventy years. Jeremiah says there would be “servitude” to Babylon (25:11) for seventy years and that the Lord would allow them to return when The Seventy Years had ended (“were completed”: 29:10).
If Daniel claims that Jeremiah said Jerusalem would be devastated for 70 years, then the writers of the book of Daniel got it wrong. The mistake could have been accidental or it could have been deliberate. This would be understandable if the generally accepted date of authorship of 167-164 BCE for the book of Daniel is correct. The writers either misread Jeremiah or they wished to misrepresent it in order to influence their contemporary audience. The manipulation of history to suit a contemporary need was not uncommon at that time.
The agrarian community was not literate. Written communication was employed by the urban elite, who naturally had the scribes. So there was probably little likelihood of the farmers and their ilk checking on the veracity of what the priests told them.
The book of Daniel is mystical in nature, with dreams being interpreted, unnatural occurrences (fire not burning, lions not eating), and Daniel is not a typical prophet, in that he did not speak to the people of God. The word “understand” (biyn) at Daniel 2 implies a spiritual comprehension, which is borne out shortly afterwards when the 70 years are reinterpreted to contain a spiritual meaning of 70 heptads.
One could reason that the writers of Daniel reinterpreted Jeremiah’s 70 years to make them run down to their own time by drawing in (conflating) the “seven times” from Leviticus 26:18,21,24,28.
This action of conflation was also taken by the writer of the books of 2 Chronicles 36:21 when he pulled in Leviticus 26:31-44 because Jeremiah did not say what he wanted Jeremiah to say. The Chronicler lived at least 200 years after Babylon fell. It is not beyond possibility that these later writers wrote the 26th chapter of Leviticus at the same time.
Doug