The Sita Upanishad is a medieval era Sanskrit text and a minor Upanishad of Hinduism. It is attached to the Atharva Veda, and is one of the nine Shakta Upanishads. It is categorized as a late Upanishad, in which goddess is extolled as the Ultimate Reality of the Universe (Brahman), the ground of Being (Spirituality), and material cause behind all manifestation. The Upanishad identifies Sita with primordial Prakriti (nature) and her three powers, asserts the text, are manifested in daily life as will (ichha), action (kriyā) and knowledge (jnana). This Upanishad is notable for asserting that the cosmos is Atman (soul), it resides in the heart, its awareness and self-realization emerges by Vichara (investigation into the Self) and Samadhi, the ultimate stage of meditation. Sita as goddess is traceable to 1st-millennium BCE Hindu texts and the Epic Ramayana. Who is Sita? That divine Being is threefold, through her power, namely, the power of desire, the power of action, the power of knowledge. —Sita Upanishad verse 11 Prajapati describes Sita as primal Prakriti, or primordial nature. She is, asserts the text, same as Lakshmi and the Shakti (energy and power) of Vishnu. The text references and uses fragments of hymns in the Vajasaneyi Samhita of Yajurveda, asserting the goddess to manifest all the times as "will, action and knowledge" that drives change in the universe, wherein everything, the empirically observed and the transcendental reality, is manifestation of her Being. Sita is all of creation, the good and the bad, all the gods and the demons, the cause and the effect, the material and the spiritual, the virtue and the beauty. Her quality includes the changing reality (Maya, metaphysical illusion), and the unchanging reality without a second (Brahman, metaphysical constant). She is free from change. She has no blemishes. She represents the vocal form of the four Vedas, which the text asserts comes from 21 schools of Rigveda, 109 schools of Yajurveda, 1000 schools of Samaveda, and 40 schools of Atharvaveda. She is ethics, tradition, law, legend, and the five minor Vedas, asserts the text, naming these as architecture, archery, music, medicine and Daivika (divinity). She is the basis of the whole world, is composed of Brahma Vishnu and Shiva, and she is the soul (inner self, Atman) that resides in all livings. Her name Sita, signifies Pranava or “Aum”, and she is the first cause of the universe. The text then offers a folk etymology for her name, asserting that each letter of her name has specific meaning. The “S” indicates Satya or eternal truth, the “i” signifies Maya or illusion in an unchanging form, and “ta” denoting the goddess of speech conjoined with Brahman. The text weaves in mythical elements of her origins. She, asserts the text, emerged at the tip of the plough symbolizing her link to Prakriti or nature that feeds and nourishes all life. She is all pervading. She, asserts the text, lights up everything in all worlds. "The wheel of time and the wheel of the Universe" are her personifications. Evolution and preservation are her gifts, she is the tree of plenty. She is Lakshmi, seated as a Yogini on her lion throne. The universe is full of the beautiful, states the Upanishad, and all that beauty is she, she alone. The Vedas are her, states Sita Upanishad, and she personifies the three goddesses: Shri (goddess of prosperity, Lakshmi), Bhumi (mother earth), and Nila (goddess of destruction). These manifestations of her, correspond to Samkhya theory of Guṇa, as Sattva, Rajas and Tamas respectively, and are traced in Vaishnavism tradition respectively to the Sri-Sukta, Bhu-Sukta, and Nila-Sukta hymns in the Vedas. Sita, states the text, is the supreme goddess, non-dual Brahman (Ultimate Reality), the Being (Spirituality), and material cause of empirical reality.