Where does Alas Babylon come from?

The phrase "alas, Babylon" comes from The Bible.

If you are talking about one of the books with the title "Alas, Babylon" however, you'll have to be more specific.

In the book "Alas, Babylon" by Pat Frank, the phrase meant that a nuclear war was coming.

But in the bible, "Alas, Babylon" means the fall of the city Babylon.