In the same way that a sesame seed is entirely permeated by sesame oil, as soon as there is clear and aware consciousness, it is said to be permeated by the clear light rigpa. This aspect of rigpa, this in-dwelling clear light is what is called essential rigpa (Tib. ངོ་བོའི་རིག་པ་ , Wyl. ngo bo'i rig pa).
- Holiness the Dalai Laman : The Heart Essence of the Great Perfection, published by Snow Lion N 1-55939-156-1
- His Holiness the Dalai Lama, The Vision of Enlightenment, Tertön Sogyal Trust. Also published by Wisdom Publications, 2007, as Mind in Comfort and Ease. The Vision of Enlightenment in the Great Perfection. ISBN : 0861714938