Part 13 · Chapter 27

And the explanation of these three heads is, that in every one of these three heads there must be the aspect of vessels, and the aspect of the essence and spirituality within it; and accordingly there will be six discernments. And each of these six discernments divides into three others, and their totality amounts to eighteen, which is the secret of the Living of the worlds [Chai Olamim]. For from these eighteen discernments the vitality spreads in all the worlds, and also in the world of Atzilut.