"Yasht" 13 begins with a cosmogonical chapter in which the Creator Ahura Mazda is portrayed as acknowledging that material creation was brought about with the assistance of "many hundreds, many thousands, many tens of thousands" of "mighty, victorious "fravashi"s" (13.1-2). Moreover, Mazda is presented as acknowledging that without the help of the "fravashi"s, cattle and men would have been lost to Angra Mainyu. "This declaration is wholly unorthodox, and unsupported by any other text." Verses 14-15, as also several other verses scattered through the text, describe how the "fravashi"s continue to sustain the material world and mankind in the post-creation phase of the world. Verses 16-17, as also several other later verses, celebrate their military prowess and assistance in battle, where they are invoked. Verse 20 includes an injunction to memorize their invocation, so as to be able to call on them in times of need.