The Shiva Purana describes the origin of the lingam, known as Shiva-linga, as the beginning-less and endless cosmic pillar (Stambha) of fire, the cause of all causes. Lord Shiva is pictured as emerging from the lingam - the cosmic pillar of fire - proving his superiority over the gods Brahma and Vishnu. This is known as Lingodbhava. The Linga Purana also supports this interpretation of lingam as a cosmic pillar, symbolizing the infinite nature of Shiva. According to the Linga Purana, the lingam is a complete symbolic representation of the formless Universe Bearer - the oval-shaped stone is the symbol of the Universe, and the bottom base represents the Supreme Power that holds the entire Universe in it. A similar interpretation is also found in the Skanda Purana: The endless sky (that great void which contains the entire universe) is the Linga, the Earth is its base. At the end of time the entire universe and all the Gods finally merge in the Linga itself. In the Linga Purana, an Atharvaveda hymn is expanded with stories about the great Stambha and the supreme nature of Mahâdeva (the Great God, Shiva).