I've read The Remains of The Day by Ishiguro Kazuo recently, and found a phrase that is difficult to read.

> If you dismiss my girls tomorrow, it will be wrong, ***a sin as any sin
> ever was one*** and I wil not continue to work in such a house.

The situaions in which this sentence is uttered are when the speaker of this sentence is complaning that the person referred to as "you" is going to fire her two subordinates dishonetly, and is denouncing him.

If you would tell me how to interpret this phrase grammatically, I'd appreciate it.