Bundahishn , meaning "Primal Creation", is the name traditionally given to an encyclopediaic collection of Zoroastrian cosmogony and cosmology written in Book Pahlavi. The original name of the work is not known.
Although the Bundahishn draws on the Avesta and develops ideas alluded to in those texts, it is not itself scripture. The content reflects Zoroastrian scripture, which, in turn, reflects both ancient Zoroastrian and pre-Zoroastrian beliefs. In some cases, the text alludes to contingencies of post-7th century Islam in Iran, and in yet other cases, such as the idea that the Moon is farther than the stars, it reiterates scripture even though science had, by then, determined otherwise.