The ARI writes that it is not adhered to the light of Ein Sof, meaning that the form of the circular light of Keter of the circles is not the same as the light in Ein Sof (Baal HaSulam “The Study of the Ten Sefirot” Vol. 1, Part 2, Chapter 1, No. 9).

Question: What is a round light?

Answer: A round light is different from any other (light) and is bound to its source. That is exactly what the Ari wants to say.

Question: Why does he call the Igulim (circles) “Sefirot” and not “Behinot“?

Answer: It is completely irrelevant now. “Sefirot” and “Behinot” are the names we use for the individual levels in each Partzuf.
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From the 2nd part of the Daily Kabbalah Lesson 9/29/2025, “The Study of the Ten Sefirot“

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