Brahman as Ananda — The Bliss That Is Being
The Taittiriya Upanishad's teaching that Brahman is Ananda (bliss) establishes that pure existence is inherently joyful — bliss is not a quality added to Brahman but its very nature.
The Taittiriya Upanishad (2.7) asks: 'Who would breathe, who would live, if this Ananda (bliss) were not in the heart of the universe?' — establishing Ananda as the motive force of all existence. Ananda is not the pleasure of satisfied desire (which requires an object, arises and passes) but the unchanging background joy that is the nature of pure consciousness itself. When the mind is still — in deep sleep, in meditative absorption, in moments of natural awe or love — this background Ananda is tasted. Brahman-as-Ananda means: the universe's ultimate nature is not suffering (as in some Buddhist formulations of samsara) but bliss. Suffering is Ananda temporarily obscured by ego-construction. Liberation is the recognition of the Ananda that was always present. The Taittiriya's 'Anandamaya Kosha' (bliss sheath — the causal body of deep sleep) is a taste of Ananda through the medium of individuality — but Brahman's Ananda is pure, not filtered through any individual medium.
From Ananda (bliss) indeed all beings are born; by Ananda, once born, they live; into Ananda they return and dissolve.
The Taittiriya Upanishad teaches 'raso vai sah' — Brahman is verily bliss (rasa) — and names the Anandamaya kosha as the innermost sheath, so that Ananda is the Self's constant underlying nature, only temporarily modified by life's vicissitudes rather than produced by outer events.
Taittiriya Upanishad