Exodus 11:1b in the Revised English Bible (REB) reads:
When he finally lets you go, he will drive you out forcibly as a man might dismiss a rejected bride.
The simile seems most unusual. Was it in the original language?
tl;dr There is no basis for "bride" in the original Hebrew.
The Hebrew text of Exodus 11:1b is:
The word which is translated by REB as "bride" is the word "כָּלָה".
The word "כָּלָה" (vocalized here with a qamatz below the kaph and no dagesh in the lamedh) means completion, especially complete destruction or annihilation.
REB confused "כָּלָה" with "כַּלָּה" (with a pataḥ below the kaph and a dagesh in the lamedh), which does, in fact, mean "bride", but has no relationship to Exodus 11:1.