From Chapter 10 ("Two Schools, One Samadhi") of No Beginning, No End: The Intimate Heart of Zen by Jakusho Kwong:

... When the focus of your practice becomes like the light of the sun penetrating a magnifying glass so sharply that it makes a fire, it dissolves greed, anger, and ignorance, the three great obstacles to our original heart/mind. Since these obstacles are no longer there, you become aware of the nature of your original heart/mind, which is vast like an ocean and pervasively very quiet, calm, and bright. Then your attitude and demeanor naturally transform. Surprisingly, more than you had ever known, you realize that you are a kind, gentle, and compassionate person. This true realization, or revelation, is due to zazen. ...

^z - 2017-04-05