Vishnupurana 1.7.12

1.7.12

tathokto 'sau dvidhā strītvaṃ puruṣatvaṃ tathākarot
bibheda puruṣatvaṃ ca daśadhā caikadhā ca saḥ //

PARÁŚARA.--From Brahmá, continuing to meditate, were born mind-engendered progeny, with forms and faculties derived from his corporeal nature; embodied spirits, produced from the person of that all-wise deity. All these beings, front the gods to inanimate things, appeared as I have related to you, being the abode of the three qualities: but as they did not multiply themselves, Brahmá created other mind-born sons, like himself; namely, Bhrigu, Pulastya, Pulaha, Kratu, Angiras, Maríchi, Daksha, Atri, and Vaśisht́ha: these are the nine Brahmas (or Brahma rishis) celebrated in the Puráńas. Sanandana and the other sons of Brahmá were previously created by him, but they were without desire or passion, inspired with holy wisdom, estranged from the universe, and undesirous of progeny. This when Brahmá perceived, he was filled with wrath capable of consuming the three worlds, the flame of which invested, like a garland, heaven, earth, and hell. Then from his forehead, darkened with angry frowns, sprang Rudra, radiant as the noon-tide sun, fierce, and of vast bulk, and of a figure which was half male, half female. Separate yourself, Brahmá said to him; and having so spoken, disappeared. Obedient to which command, Rudra became twofold, disjoining his male and female natures. His male being he again divided into eleven persons, of whom some were agreeable, some hideous, some fierce, some mild; and he multiplied his female nature manifold, of complexions black or white.