Daniel 9:1-2

In the first year of Darius the son of Ahasuerus, of the seed of the Medes, who was made king over the realm of the Chaldeans, in the first year of his reign I, Daniel, understood by the books the number of the years whereof the word of Jehovah came to Jeremiah the prophet, for the accomplishing of the desolations of Jerusalem, even seventy years.