Where was the concept of an "evil twin" first used?

I was going to say when me and my sister was born and they met me, but Wiki says it goes back before that:

"The similarities and differences of twins has long held a fascination for writers. Perhaps the oldest depiction of this idea is the biblical story of Cain and Abel in which one brother is the jealous counterpart of the other. Dualism and the conflict between good and evil is an important element in religion and mythology.
The concept also has its roots in the notion of a doppelgänger, a ghostly double whose appearance is an ill omen. The evil twin expands on this by being concrete and interacting physically with the world."

https://en.wikipedia.org/wiki/Evil_twin

Someone put the umlaut on doppelgänger. I'm so happy I could cry.

I think Jacob and Esau had more to do with the concept of the evil twin than Cain and Abel (Jacob and Esau were twins, Esau was portrayed by legend as the evil one).

As for the doppelgänger stories, the doppelgänger itself is not really an evil twin, but more of a shadowy double who imitates one exactly.

Doppelgänger, in the German dictionary, is defined as 'exact double'. You can also be a female Doppelgänger, of course. That would be 'eine Doppelgängerin'.

I love German.

Yesterday, I tried to echo the Jacob/Esau comment and ask if doppelgänger originated in Germany or if the legend/myth goes back further. Then my computer froze.

Good thing though, I figured out how to get the umlaut on there without as much trouble as I was planning.

Umlauts are easy. The real trouble is when you're trying to transliterate Semitic words or names directly into Roman characters (such as "Ya'akov") as music lyrics, and have to go syllable by syllable worrying about apostrophes and the problems they might cause. Transliterating Hebrew in music is so much easier to do by hand, but actually typing it in Hebrew is almost impossible to do in a music program, especially one that's not equipped to handle lyrics...

Yes, I figured out how to insert the symbol, but when the computer froze and I had to try again, I realized I could just cut and paste the whole word and skip it the whole thing.

I really should learn another language; my Spanish class in high school was a joke.