The Numerical Laws

The law of the Three and the law of the Seven are fundamental in the cosmology of Gurdjieff, and of course, have parallels in other religious paths. The Hindu Trimurti, for example, is reminded to us in Peter Brook's movie Mahabharata.
For one example in Jewish thought we can look in The Book of Creation, Sefer Yetzira, considered one of the oldest documents in Jewish mysticism. The short book is traditionally attributed to the patriarch Abraham, and modern studies find traces for it as early as the 2nd century AD.
I will now sin by, out of context quotes (Aryeh Kaplan translation):

"Three Mothers... are fire, water, and breath. The hot is created from fire, the cold is created from water, and the temperate from breath decides between them."

"Seven... Seven and not six, seven and not eight. Examine with them and probe from them, make each thing stand on its own essence, and make the Creator sit on His base."

I encourage you to read the full book. It contains much more. Here I would just say that it actually refers to the numbers 3, 7, and 12, that their sum, 22, is the number of letters in the Hebrew alphabet.

Any metaphysical multiplicity discussion in Judaism is EXTREMELY risky. ALWAYS remember that there is only ONE. ReMember, we are only talking about observable laws of a created cosmos. There is nothing we can say or even think about the creator.

Practice. The theory is secondary.