The Mundak Upanishad is said to have been imparted by Lord Brahma to his eldest son Atharva. Thus it is a part of the Atharvaveda. The name of the Upanishad comes from the word mund (to shave), the metaphor being one who has been liberated from his ignorance.
The Upanishad contains three chapters, each of which is called a mundak. These chapters are further divided into sub sections, called khanda. The Upanishad is in the form of a mantra, containing a total of 64 verses.
The Mundak Upanishad preaches that there are two types of knowledge (vidyaa). Paraa vidyaa, the higher one, is the knowledge of the Brahman. Aparaa vidyaa, the lower one, is the knowledge of the physical world. The Upanishad goes on to say that all knowledge collected by mankind - phonetics, grammar, etymology, even the teachings in the Vedas, is aparaa vidyaa. Only the true knowledge of the Supreme Being is paraa vidyaa.
As the spider sends forth and draws in its thread, as plants come up from the earth, as hair grows on a living person, the universe arises from the Impershable.