‘Adam’s ale’
Adam’s ale, of course, doesn’t refer to the world’s first beer but is rather another way of referring to water, stemming from the idea that water would be all that the first man had to drink in the Garden of Eden.
Specifically, Adam’s ale is pure water that hasn’t been adulterated in any way, such as he would have drunk. The phrase became particularly popular during the temperance movement on the 1830s, which promoted water as a pure and healthier alternative to alcohol.