Doves are the most loyal mates of all creatures in nature. Doves never remate. This instinctive loyalty is expressed in their gaze. Mated doves continually gaze upon one another, never tiring of the unbounded pleasure of beholding the beloved. For the soul, this state of serving G-d is called "L'istakla biy'kara deMalka ("to gaze at the splendor of the King"). Above and removed from letters of thought, the inner eyes of the mind and heart behold with boundless pleasure the splendor of the King in His Infinite greatness and beauty until mind and heart merge in complete selflessness (bitul). All pleasures of self are limited and must ultimately come to an end, but selfless pleasure is endless and perpetually new.
At the level of "my dove" the seemingly, opposite properties of "my sister" and "my companion are unified. The love represented by the phrase "my dove" is both constant, like the continuous, instinctive love expressed in "my sister", and new, like the newborn, burning love expressed in "my companion". This ability to unify water and fire depends on the manifestation of the power of bitul, which is innate in the soul of every Jew. The service of gazing demands giving oneself over completely to the King.
