Translation
Two women are grinding with the mill,
one is received
and one is rejected.
Paraphrase
Two women are working together at their daily tasks as they always do, one is received and rewarded because she is righteous, one is rejected and punished because she is not righteous.
One Is Received, One Is Rejected
This refers to when the Son of Man makes His appearance in full power and glory. It will have nothing to do with the Romans or any other political power; it will have everything to do with bringing punishment and reward to each individual. If this event were predictable or expected, both individuals in each case would be ready for it. But the time of completion will be unexpected.
If one believes in a rapture of the saints along the lines of the timelines promoted by most modern prophecy experts, the words “taken and left” make perfect sense and do not raise any eyebrows. However, please understand that such an interpretation is not the only one possible, in fact, another is just as viable, if not more so. The primary meaning of the first word is “to receive, or take;” the primary meaning of the latter is “to send, or to send away.” This fits perfectly with an understanding of prophecy which states simply that Jesus will return to reward the righteous and punish the wicked. I believe that is the intended meaning here.
Prophecy experts have developed an elaborate timeline that says that several thing must happen before the final judgment. I am convinced that we cannot know how these things will play out and the book of Revelation is not about the future; it is intended as encouragement for those suffering under persecution or intense opposition. It is possible that some things will happen between the moment when Jesus returns and when judgment is rendered, or it is possible that it will be swift and immediate. However, the pattern in Scripture, is that when a powerful ruler shows up on the scene, he takes action quickly, with no delays. We cannot be sure about this, but my guess would be that when Jesus makes His appearance as the ruler and judge over all creation, His judging will be immediate.