Chandogya Upanishad 3.5

The upward rays of the sun are the honey-cells above. The secret doctrines are the bees, Brahman (the Om) is the flower, the water is the nectar.

Those secret doctrines (as bees) brooded over Brahman (the Om); and from it, thus brooded on, sprang as its (nectar) essence, fame, glory of countenance, brightness, vigour, strength, and health.

That flowed forth, and went towards the sun. And that forms what seems to stir in the centre of the sun.

These (the different colours in the sun) are the essences of the essences. For the Vedas are essences (the best things in the world); and of them (after they have assumed the form of sacrifice) these (the colours rising to the sun) are again the essences. They are the nectar of the nectar. For the Vedas are nectar (immortal), and of them these are the nectar.