Never knew that - always supposed that, OK, it looks like “What!” and was pronounced more-or-less the same.
Oh, those goofy Anglo-Saxons.
Oh my gosh.
You need to type it into a search bar and read the zillions of posts by people arguing various possibilities.
After “So!” my next favorites are “Behold!” and “Lo!”
One guy said it’s the ancient version of “Bruh”.
This is one of the best linguistic rabbit holes, ever.
😄