I see what you mean, Joe F. (I remember once hearing a grizzled miner in Utah cooing to his little dog, "You hop out and get you a drink.") Still, I would like to hear from somebody who speaks German well and is familiar with older literature.

I've seen facsimilies of Bach's handwriting, and it was not good. Or perhaps when he wrote the words down, one of his twenty children was talking loudly near him, and he heard "dir" and wrote it when he meant "mir."

The main question is, has this construction ever appeared elsewhere?