Pure Consciousness Resides in Every Being – Upanishads

Like butter hidden in milk, pure consciousness resides in every being. It ought to be constantly churned out by the churning rod of the mind. (Amritabindu Upanishad, 20)

As oil is in the sesame seed, butter in curd, water in flowing waves, and fire in wood, so is the Atman in oneself. It is to be discovered by one who searches for it through truth and tapasya. (Brahma Upanishad, 17)

Just as a disc covered with mud shines as full of light when washed well, similarly the embodied being, seeing the reality that the Atman is, becomes non-dual, self-fulfilled, and free from sorrow.  (Shvetashvatara Upanishad, 2.14)

He by whom the space between heaven and earth, as well as heaven and earth, are enveloped; he because of whom the sun burns with heat and gives light; and he whom the sages bind in the space within their hearts (through meditation), in that Imperishable one all creatures abide. (Mahanarayana Upanishad, 1.3)