Yesod is then the ninth sphere, or ninth Sephirah and represents the sexual organs, and Tiphereth is the sixth Sephirah and represents the heart. The addition of these two spheres makes 15 (6 + 9 = 15). This is the Kabbalistic interpretation resulting in the Devil, Temptation, Arcanum 15 of the Tarot.
6 + 9 = 15
Tiphereth and Yesod = Tiphon- Baphomet
Who is the Devil?
