The horse that was brought for the HorseSacrifice was let loose, according to the injunctions of the scriptures, by that utterer of Brahma, viz., Vyasa himself of great energy.
हयश्च हयमेधार्थं स्वयं स ब्रह्मवादिना। उत्सृष्टः शास्त्रविधिना व्यासेनामिततेजसा॥