Exodus 11:1b in the Revised English Bible (REB) has: 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?
The Hebrew for this passage is:
Here's a phrase-by-phrase translation (mine, guided by the linked one):
אַחֲרֵי-כֵן -- afterwards
יְשַׁלַּח אֶתְכֶם מִזֶּה -- he will send you from this (anaphora unresolved, but from context "here")
כְּשַׁלְּחוֹ -- when he will send you
כָּלָה, גָּרֵשׁ יְגָרֵשׁ אֶתְכֶם מִזֶּה. -- altogether he will surely thrust you out from this (anaphora again)
Some notes: where I translated "send" many say "let you go"; it's a causitive verb, so both of those work. The "surely thrust" translation comes from the doubling of the verb גָּרֵשׁ; when we see this pattern it's usually an intensifier, and "shall surely (verb)" is a common way to render that.
But the apparent source of the difficulty in the translation you quoted is the word כָּלָה, Strong's H3617, which means here "altogether" or "completely". This word is very similar to the word for bride, כַּלָּה, which is Strong's H3618 (note the difference in the first vowel, and the dageish in the lamed). I suppose if a translator understood the word to be "bride" then he might come up with something like the REB translation, which would (with some punctuation changes) call for rendering the last part of this as a comparison to a bride rather than "he will surely thrust you out", referring to Paro sending the Israelites out of Egypt.
But wait, you might say, vowels aren't original to the text, so maybe it did say "bride" and the Masorites changed it. I'm not fluent in Aramaic myself, but I note that Rashi talks about Onkelos's translation (targum) into Aramaic in the first century of the common era:
Finally, I note that the compilers of Strong's lexicon read it as כָּלָה (altogether), not כַּלָּה (bride).