It’s a question that Kabbalah, Jewish mystical tradition, wrestles with constantly. And it brings us to a fascinating concept: the "beating" of light.
Now, before you picture cosmic fisticuffs, let's unpack this a bit. We’re talking about the interplay between two types of light: the inner light and the surrounding light. To understand this, we need to talk about partzufim (divine countenances) and a concept called ovyut (opacity) and kashyut (hardness).
Imagine a partzuf as a vessel, a container meant to receive and hold divine light. But this vessel isn't perfectly transparent. It has a “partition,” a barrier with varying degrees of ovyut and kashyut. These qualities represent the resistance, the "opaqueness" and "hardness," that the vessel presents to the light.
According to Petichah LeChokhmat HaKabbalah, these forces of opacity and hardness impact the surrounding light, which yearns to be enclothed within the partzuf. Think of it like trying to pour water into a container with a small opening—some spills over. The partition impacts the light, preventing it from fully entering in the same way it impacts the supernal light during fusion. This impact, this push and pull between the surrounding light and the opacity of the partition, is what's called the "beating of the surrounding light on the inner light."
But here's a crucial detail: this "beating" only occurs within the "body" of the partzuf. Why? Because it’s in the body that we can truly discern the enclothing of light in the vessels, leaving the surrounding light outside. In other words, it is only in the body that light can truly be defined as inner versus surrounding.
The text contrasts this with the "head" of the partzuf. The ten sefirot (divine emanations) of the head don't experience this "beating." That's because the returning light in the head isn't considered true vessels, but rather "thin roots," potential vessels waiting to form. The light within the head's vessels isn't truly circumscribed as "inner light," so the remaining light can’t be comparatively considered "surrounding light."
The Petichah LeChokhmat HaKabbalah explains this further: the head of the partzuf represents the theoretical potential, the blueprint for forming proper receiving vessels. The body, on the other hand, is the actualization of that process. Only when the partzuf is complete, with both head and body, can we truly speak of inner light (the supernal light received in the body's vessel structure) and surrounding light (the supernal light that remains outside). As explained in the note to section #33, you can think of the head of the partzuf as referring to the theoretical potential of the process of forming proper receiving vessels, while the body of the partzuf is the actualization of the process.
So, what does all this mean for us? It's a reminder that receiving and containing light – whether divine, intellectual, or emotional – is a dynamic process. There's always a tension, a push and pull, between what we internalize and what remains outside. Perhaps by understanding this "beating," we can become more conscious of the boundaries we create and how they shape our experience of the world.