These two Brahmanas are actually Suresvara's exposition of Sankara's Bhasya on the first chapter of the Brhadaranyakopanisad. They form a sequel to his almost independent treatise, The Sambandhavartika, wherein he has dwelt upon the doctrine that ritual is also useful to one in one's effort to attain liberation, for it purifies first the intellect and then the individual self, thereby paving way to the rise of the knowledge about the reality, i.e. to liberation. He then turns to explain ---following the Brhadaranyakopanisad itself--- how the horse sacrifice, the most prominent among the various rituals, becomes useful to one in attaining the knowledge about the reality: this on the basis of (i) the Upanisadic sentences vidyaya va karmana va and tadd haital lokajid eva and (ii) Sankara's statement that Asvamedha secures for one the reward in the attainment of the knowledge of collectivity and individuality of the one Real, viz. Atman (samastivyastiphalatva). This forms the beginning of Brahmavidya 'the lore of the Brahman'. Naturally, it begins with the explanation of transmigratory or worldly existence of an individual and the statement that the pursuit of this ritual as worship of the deity Aditya (or variously called as Agni and Arka) leads one to the knowledge of the Hiranyagarbha, the first and subtlest manifestation of the Brahman--- thus, it forms the first step of one to liberation.