Nun, spelled in full: Nun Vau Nun

Nun is the fish, attributed to Scorpio and Death.
Vau is the nail, attributed to Taurus and The Hierophant.

The path of Nun leads from Netzach to Tiphareth, from the highest Sephira in the triad of the personality to the Sephira of the Inner Sun of Light and Life. This is a path of the dissolution of the outer persona. The Hierophant is the Voice of Wisdom and the Expounder of the Mysteries. It is this that we come to know when the outer has been stripped away and we reside alone in the void of self-hood.

When one letter is surrounded on either side by another it is an indication that what is represented by the letter in the center is to be found within the midst of the process symbolized by the surrounding letter. In the case of Nun, we rise above the level of the outer self as the LVX dawns within us, only to be plunged into the vast sea of the unconscious in which we lose our sense of self. The Voice of the Higher is found within these hopeless depths. It is for this that the fish hook of Tzaddi is cast into those waters. This is the inner Wisdom which leads us from the chaos of the void and of night into the Light of Tiphareth, this is the initiator that leads us to the higher life of the Inner Sun. Were it not for this voice, the waters of the unconscious would be a place of darkness and obscurity in which we would never find our way. The Hierophant is the power which leads to regeneration from the waters of death.

Taurus is opposite Scorpio on the zodiacal wheel. The arrangement of letters in Nun mirrors that of the next letter, Mem, in which a letter signifying fire (Yod) is found between two instances of a letter signifying water (Mem). In this case, it is a stabilizing force that is found within the chaotic waters of Nun. In Tiphareth, the Voice of the Hierophant becomes the new foundation of the aspirant's self-hood, which is no longer fully based in the old persona. That persona is revealed to be a mere mask, obscuring the true Self. The Higher Will now replaces the will of the persona, though it typically takes several years for this process to come to full fruition.