BLB(i)
25 Take heed lest you refuse the One speaking. For if they did not escape, having refused the One divinely instructing them on earth, much less we, turning away from the One from the heavens,
26 whose voice shook the earth at that time; but now He has promised, saying, “Yet once more I will shake not only the earth, but also heaven.”
27 And this, “Yet once more,” signifies the removing of the things being shaken, as having been created, so that the things not being shaken should remain.