Jesus made a curious statement as part of His Olivet discourse: "Pray that your flight may not be in winter or on a Sabbath" (Matthew 24:20). I consider this to be a reference to the chaos surrounding the Roman destruction of Jerusalem. However, my point below is even greater for those who insist that He is talking about some future tribulation.
The reason that this sentence strikes me is because of His reference to the Sabbath. So many Christians claim that He fulfilled the Sabbath, so that it has no continuing significance. They often, but improperly, cite Colossians 2:16 to support this view.
However, the words of Jesus here indicate that He, at least, had no expectation of the cessation of the Sabbath. He anticipated that Christians would still be honoring it, and the concomitant command to cease from labor, at least forty years after He spoke these words!
This sentence is a major difficulty for the dispensationalist. First, he has been taught, erroneously though it be, that the Sabbath was part of the Law, and we "are under grace, not under Law" (Romans 6:14). Therefore, his hermeneutical presuppositions make no allowance for the future Sabbath. Second, he has been taught that Matthew 24 is about a tribulation that will happen just before the return of Jesus, sometime in the future. Therefore, by his own theological axioms, the words of Jesus require a continuing recognition of the Sabbath for at least two thousand years since the words were spoken. This one sentence completely overturns the dispensational hermeneutic.