The Millennium doctrine of Revelation 20 seems strange to many Christians because a specifically one thousand year future period is not mentioned anywhere else in the Bible. Yet a future time in which the Messiah will rule on this earth is a common prophetic theme. It’s only the length of this period of time that isn’t mentioned elsewhere. But the prophets foretold not only the coming reign of the Messiah. They also mentioned other details of the Millennium teaching long before the time of the New Testament.
There are many beautiful expressions in the Bible that slip by translators for one reason or another. One of these is the phrase “a generation of generations” (dor dorim). Most translate it “through all generations” or something similar. This does capture the idea in a general sort of way. But as Jesus taught, in God’s Word even the smallest letter and stroke of the pen is important (Matt. 5:18). In fact, this simple expression captures an amazingly beautiful insight into the resurrection: that the final generation of mankind will be a single generation made up of many generations.