“40Then two men will be in the field: one will be taken and the other left. 41Two women will be grinding at the mill: one will be taken and the other left.”
ONE TAKEN AND ONE LEFT – Jesus explained His coming (Parousia) would be similar to when the flood came taking the unbelievers away in judgment and leaving Noah behind in the ark. Two people will be together; one will be taken and the other left. His point is that people will be doing what they normally do, and that His outpouring of wrath will catch them by surprise.
See parallel passage in Luke 17:34-37. The Lord says: “one will be ‘taken’ and the other Left.” He is asked the question in Verse 37 – “Where, Lord?” Answer: “Wherever the body is, there will the vultures be gathered together.” This same kind of death and judgment is discussed in Matt. 24:40-41 where one would be taken and the other left. And that is precisely how the Roman armies rampaged the towns – they killed one and left one to carry on their slave works in the fields. Murdering multitudes, taking many into captivity to be sold as slaves, but also leaving a trace of workers to do the manual work as slaves in their own farms and cities to keep the area running. This verse in Luke is in direct reference to Isa. 34:5, 15 – the same slaughter and gathering together of the vultures to feast on all of the piled up dead bodies of the Edomites. And also in reference to the final end of the Old Covenant Jewish nation as depicted in Rev. 19:17 with the angel of the Lord crying out to the vultures to gather for the feast on the carnage. (Note: Josephus reported that the devastation was so great that nearly 50,000 Jews were taken by the Romans into captivity and more than a million Jews were killed.)
[For a more in-depth study see eschatology “Study Series 7 Lesson 5 Matt. 24:32-44”]