Mbh 13.85.10a

"'"Vasishtha continued, 'This history also, O Rama, called Brahmadarsana, was heard by me in days of yore, respecting the achievement of the Grandsire Brahman who is identifiable with the Supreme Soul. To a sacrifice performed in days of yore by that foremost of gods, viz., Lord Rudra, O thou of great might, who on that occasion had assumed the form of Varuna, there came the Munis and all the deities with Agni at their head. To that sacrifice also came all the sacrificial limbs (in their embodied forms), and the Mantra called Vashat in his embodied form. All the Samans also and all the Yajushes, numbering by thousands and in their embodied forms, came there. The Rig-Veda also came there, adorned with the rules of orthoepy. The Lakshanas, the Suras, the Niruktas, the Notes arranged in rows, and the syllable Om, as also Nigraha and Pragraha, all came there and took their residence in the eye of Mahadeva. The Vedas with the Upanishads, Vidya and Savitri, as also, the Past, the Present, and the Future, all came there and were held by the illustrious Siva. The puissant Lord of all then poured libations himself into his own self. Indeed, the wielder of Pinaka caused that Sacrifice of multifarious form to look exceedingly beautiful. He is Heaven, Firmament, Earth, and the Welkin. He is called the Lord of the Earth. He is the Lord whose sway is owned by all obstacles. He is endued with Sri and He is identical with the deity of blazing flames. That illustrious deity is called by various names. Even He is Brahman and Siva and Rudra and Varuna and Agni and Prajapati. He is the auspicious Lord of all creatures. Sacrifice (in his embodied form), and Penance, and all the union rites, and the goddess Diksha blazing with rigid observances, the several points of the compass with the deities that respectively preside over them, the spouses of all the deities, their daughters, and the celestial mothers, all came together in a body to Pasupati, O perpetuator of Bhrigu's race.