Came across this sentence in a memoir and I have a grammar question about it. For context, a person is thinking about someone sleeping nearby:
Regarding 「残るは」, is this a set phrase or expression? It's not a nominalized verb, as far as I can tell, as those typically possess the particle の, or こと. And I've seen it pop up in other things I've read. I understand the general meaning as:
The guy who spoke up earlier won't be asleep for some time. That leaves the guy next to him（隣の隣）, who I'm not sure is asleep.
Yet why is 残る left with は, as opposed to こと or の? Is it functioning in a similar way to には after a verb, whereby it doesn't need to be nominalized with こと or の? Given the very modern context of the memoir I'm not convinced it's a case of classical Japanese slipping in, but it might be a fixed expression used more generally in certain situations? It's hard to say.