The phrase “As Above, So Below” is attributed to the Emerald tablet, an Egyptian-Greek wisdom text from the 2nd and 3rd centuries CE, which was regarded by European alchemists as the foundation of their art and its Hermetic tradition.
One line in the text as translated into English reads: “That which is Below corresponds to that which is Above, and that which is Above corresponds to that which is Below, to accomplish the miracle of the One Thing.”
This maxim appears to be a testament that there is a connection between all things and that because everything is energy and vibration, everything is connected.