tapo me hrdayam brahmams
tanur vidya kriyakrtih
angani kratavo jata
dharma atmasavah surah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
My dear brahmana, austerity in the form of meditation is My heart, Vedic knowledge in the form of hymns and mantras constitutes My body, and spiritual activities and ecstatic emotions are My actual form. The ritualistic ceremonies and sacrifices, when properly conducted, are the various limbs of My body, the unseen good fortune proceeding from pious or spiritual activities constitutes My mind, and the demigods who execute My orders in various departments are My life and soul.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Sometimes atheists argue that since God is invisible to their eyes, they do not believe in God. For them the Supreme Lord is describing a method by which one can see God in His impersonal form. Intelligent persons can see God in His personal form, as stated in the sastras, but if one is very eager to see the Supreme Personality of Godhead immediately, face to face, he can see the Supreme Lord through this description, which portrays the various internal and external parts of His body.
To engage in tapasya, or denial of material activities, is the first principle of spiritual life. Then there are spiritual activities, such as the performance of Vedic ritualistic sacrifices, study of the Vedic knowledge, meditation upon the Supreme Personality of Godhead, and chanting of the Hare Krsna maha-mantra. One should also respect the demigods and understand how they are situated, how they act and how they manage the activities of the various departments of this material world. In this way one can see how God is existing and how everything is managed perfectly because of the presence of the Supreme Lord. As the Lord says in Bhagavad-gita (9.10):
“This material nature is working under My direction, O son of Kunti, and it is producing all moving and nonmoving beings. By its rule this manifestation is created and annihilated again and again.” If one is unable to see the Supreme Lord although He is present as Krsna in His various incarnations, one may see the Supreme Lord’s impersonal feature, according to the direction of the Vedas, by seeing the activities of material nature.
Anything done under the direction of the Vedic injunctions is called dharma, as described by the order carriers of Yamaraja (Bhag. 6.1.40):
hy adharmas tad-viparyayah
vedo narayanah saksat
svayambhur iti susruma
“That which is prescribed in the Vedas constitutes dharma, the religious principles, and the opposite of that is irreligion. The Vedas are directly the Supreme Personality of Godhead, Narayana, and are self-born. This we have heard from Yamaraja.”
In this connection, Srila Madhvacarya comments:
tapo ’bhimani rudras tu
visnor hrdayam asritah
vidya rupa tathaivoma
visnos tanum upasrita
angesu kratavah sarve
madhya-dehe ca dharma-rat
prano vayus citta-gato
brahmadyah svesu devatah
The various demigods are all acting under the protection of the Supreme Personality of Godhead, and according to their various actions the demigods are differently named.