Mrigashira is the Lunar Mansion which spans the last degrees of Taurus and the beginning degrees of Gemini. Taurus is ruled by Venus, our senses, and Gemini is ruled by Mercury, our intellect, discriminative ability. Mrigashira is the energy of the tamasic aspect of Mars (our will power, determination) which allows us to use our strength of will to discriminate (Mercury) between the sensory pleasures (Venus) that serve us and those that do not and to break free of addictions and attachments.
The tamasic Mars represented by Mrigashira allows us to use our will power to cut through the illusiory temptations of the senses and realize our true nature as pure awareness, the silent inner witness. As we allow this we reach a state of deep inner rest which is the gift of Mars the warrior, bringing death to all illusion and allowing us to rest in the pure Presence of our Being.