The first two chapters of the Kanva-recession of the Brhadaranyaka-Upanisad Volume I are, in the Madhyandina-school, included not in the Upanisad portion (Volume XIV) of the Satapatha-Brahmana but in Volume X of the text, i. e. “Agnirahasya (mysterious doctrine of the Agnicayana)”. In this article I point out that these chapters originally belonged to the Agnirahasya, showing that the wording and the logical construction are common to that of the Agnirahasya.
The main theme of these chapters is the overcoming of re-dying (punarmrtyu-) through the Asvamedha, and this is theologically explained with the interpretation of the relation between the Agnicayana, which is included in the Asvamedha, and the horse sacrifice (asvamedhá-).
These chapters can be understood only in a ritualistic and theological context, and so these points are especially discussed: 1) arká- denotes the fire altar of the Agnicayana. 2) “Death (mrtyú -)” symbolizes not Prajapati as has so far been supposed, but the sun and at the same time the golden Purusa (afigure) used in the Agnicayana. 3) This theological interpretation is based on and developed from the Brahmana interpretation of an oblation (arkasvamedháyoh sámtati-) which is performed in the Agnicayana.