John Walvoord, in his book called (The Millennial Kingdom, page 227) admits this weakness as follows. “While the most literal interpretation of the first 69 weeks is thus afforded a literal fulfillment, nothing can be found in history that affords a literal fulfillment of the last 7 or the Seventieth Week. It has been taken by many that this indicates a postponement of the fulfillment of the last seven years of the prophecy to the future preceding the Second Advent. If so, a parentheses of time