What Does "Dot-Letter-Word" mean?

First there is a dot, beyond words, beyond sounds, beyond thoughts, beyond ideas...
Then it coalesces, it descends into the mind, it begins to appear, it crystallizes, it gains identity, it is a crystal, a hard entity, a letter.
Then it expands, it unfurls, it explains itself, it speaks, it reveals a thought, it stands open to scrutiny, a word.

From a Hasidic Teaching:
            Holy passions that were shattered and fell are repaired by a constricted light. That constricted light is a black dot.
            They shattered because there was too much light, which overwhelmed a person so that his holy passions were directed into fallen, unholy channels….
            There is a sign, a letter, the foundation. It is the light that repairs the shattered vessels….
            The light of the black dot … shines when it is illuminated by the light of the mind. Then the dot shines. Those are words: “My mouth will speak wisdom.” And then light shines onto the heart.
     Likutei Halachot: Orach Chaim, Hilchot Tefillin 2