Sri Aurobindo translates Katha Upanishad, Second Cycle: First Chapter, Verses 4-5: “The calm soul having comprehended the great Lord, the omnipresent Self by whom one beholds both to the end of dream and to the end of waking, ceases from grieving. He that has known from very close this Eater of sweetness, the Jiva, the self within that is lord of what was and what shall be, shrinks not thereafter from aught nor abhors any. This is That thou seekest.”
The soul, the Jivatman, is the divine consciousness embedded in the human being. This transcends the “waking” awareness, wherein we perceive the outer world of the senses and the “dream” awareness, wherein we experience the subjective life of the vital and mental plane. Once the soul has shifted the standpoint from the outer consciousness to the divine consciousness, there is no longer any basis for grief, which is an ego-reaction to events in life seen from the individual standpoint. Similarly, the soul is known as the “Eater of sweetness” because it is the conscious entity that enjoys the manifestations of the world, the pleasure and pain, the joy and grief, the success and failure that the individual experiences.
The divine consciousness has a different relationship to Time as well. Past, present and future for the ego-personality limit and define the life-span; but for the divine consciousness, they are all incorporated into one continuous awareness.
Once the soul recognizes the Oneness of all creation, there is no cause for fear, which is, once again, a reaction of the limited egoistic personality to the apparently separate and distinct beings, forces and actions that take place in the world. The Soul has no fear, as the Taittiriya Upanishad explains: “for when the Spirit that is within us findeth his refuge and firm foundation in the Invisible, Bodiless, Undefinable and Unhoused Eternal, then he hath passed beyond the reach of Fear. But when the Spirit that is within us maketh for himself even a little difference in the Eternal, then he hath fear, yea, the Eternal himself becometh a terror to such a knower who thinketh not.” (Taittiriya Upanishad, Brahmanandavalli, Chapter 7, in Sri Aurobindo, The Upanishads, pg. 271)
Sri Aurobindo, The Upanishads, Katha Upanishad, pp. 213-241, and Kapali Sastry, Lights on the Upanishads, pp. 104-129