Behold, I tell you a mystery. We will not all sleep, but we will all be changed,
ExplanationCommentary
Verse 51. We shall all indeed rise again, but we shall not all be changed. [3] This is the reading of the Latin Vulgate, and of some Greek MSS. and the sense is, that all both good and bad shall rise, but only the elect to the happy change of a glorified body. The reading in most Greek copies at present is, we shall not all sleep, (that is die) be we shall be all changed: so also read S. Chrysostom: and S. Jerom found it in many MSS. from which divers, especially of the Greek interpreters, thought that such as should be found living at the day of judgment should not die, but the bodies of the elect (of whom Saint Paul here speaks) should be changed to a happy state of immortality. This opinion, if it deserve not to be censured, is at least against the common persuasion of the faithful, who look upon it certain that all shall die before they come to judgment. Some expound the Greek only to signify, that all shall not sleep, that is shall not remain for any time in the grave, as others who die are accustomed to do. Witham.
“Behold”, from “ἰδοὺ”, means look at, take notice, observe, see, or gaze at. It is often used as an interjection.