Chandogya Upanishad
Prapathaka III, Khanda 4
The northern rays of the sun are the honey-cells on the left. The (hymns of the) Atharvâṅgiras are the bees, the Itihâsa-purâna (the reading of the old stories) is the flower, the water is the nectar.
Those very hymns of the Atharvâṅgiras (as bees) brooded over the Itihâsa-purâna; and from it, thus brooded on, sprang as its (nectar) essence, fame, glory of countenance, vigour, strength, and health.