No, since Ephraem the Syrian espoused this viwe as well, way back in A.D. 373. He wrote,
Not to nitpick, but that was probably pseudo-Ephraem. The actual Ephraem was, from most of his other writings, pretty solidly post-millenial.
Also, assuming that what you quoted does support a rapture, is there any evidence that that was accepted doctrine by any Christian, or just an isolated statement by (pseudo?) Ephraem?
I think the issue of whether this was Ephraem or pseudo-Ephraem is irrelevant. The point is that this teaching predates Darby by several centuries.
We surely don’t have enough information to determine how commonly accepted this teaching was, especially given the relative dearth of writings from that era. Once again though, that’s irrelevant to the question of whether it originated with Darby or not.
The theory that’s supposed to have originated with Darby is dispensational premillenialism… But I think the popularity of the theory is relevant. If somebody in the 4th century mentions in passing a theory of “the rapture”, and the idea is ignored, then, in the 19th century, somebody else comes up with a similar rapture theory, that doesn’t mean there’s neccesarily continuty between the two theories. Darby could have come up with his rapture theory without any knowledge of pseudo-Ephraem… We don’t have evidence that early Christianity believed in the rapture theory…we have evidence that psudo-Ephraem did, but we don’t know to what extent his ideas were accepted, or if he was just seen as a crackpot. And, considering that he makes the statement in the 3rd-6th century, and then nobody else talks about it till the 19th century, suggests that, until the 19th century, it wasn’t seen as normative doctrine.