The Upanishad has revealed three forms in which the transcendental Brahma-tattva manifests Itself. The three forms are: Virata; Hiranyagarbha; and Avyakrita. These three farms are related to the gross, the subtle and the causal (forms of the human body). They are related to the three states of consciousness: Waking, dream and deep sleep.
Virata, Hiranyagarbha and Avyakrita are not entities existing in some separate place. When you examine carefully, you will find that every human being is an incarnation of ‘Virata’, of ‘Hiranyagarbha’ and ‘Avyakrita’. This profound truth is not realised by men because of their narrow outlook: The Virata-form (Cosmic Person) is the human body multiplied by infinity. Mind x Infinity = Hiranyagarbha; Life x Infinity = Avyakrita. These three forms are related to the gross, the subtle and the causal bodies of man. All the three bodies are in the human being. (SSS Vol. 24)