Like the Īśāvāsya Upaniṣad, the first in the series of the ten Upaniṣads considered ancient and more important, the Kena Upaniṣad (which is the second) also derives its name from the very first word, ‘kena’ (‘by whom’) with which it begins. Since it belongs to the Talavakāra Brāhmaṇa of the Sāmaveda, it is also known as the Talavakāra Upaniṣad. The talavakāras were those who could sing the Sāmans with tāla or keeping time with regular beats of hand. (This seems to have gone out of practice in later years.)
It has four khaṇḍas or sections, the first two being in poetry and the last two in prose. The total number of verses is 35.
The Upaniṣad opens with a question, perhaps by an inquiring disciple, whether there is any entity behind the sense-organs like the ear or the organ of speech or even the mind, that impels them to work. The teacher replies that there is, and that he is the eye of the eye, the ear of the ear, the speech of the speech and the mind of the mind. They are able to function because of his presence and power. They do not know him whereas he knows them all. He is Brahman. It is almost impossible to impart the knowledge concerning him to others since his characteristics are beyond the comprehension of the senses and the mind.
Since Brahman (as the ātman in us, our very Self) is the real knower of all that is known through the senses and the mind and itself is not an object of knowledge, one can never say that one has known him nor not known him. Awareness of Brahman is felt at every moment of our life. It is only the direct experience of this ātman that gives us real strength and immortality. If one misses the grand opportunity given through this human birth for getting that experience and immortality through it, it is a terrible loss. This is the gist of the teaching of the second section.
The third section teaches through an interesting story that Brahman is supreme and that even the gods in heaven, like Indra and Agni, could win their battles against the asuras or demons only because of the power imparted to them by him. They were made to learn this bitter lesson after being humiliated by Brahman disguised as a yakṣa, a demigod, far inferior to them!
The fourth section is a continuation of the teaching of the third. It is the goddess Umā Haimavatī that is teaching Indra, the king of the gods. Brahman who appeared before Indra just for a moment like lightning is also the ātman, the Self in every one of us. One has to meditate upon him as ‘tadvana,’ ‘the one who is highly desirable’. This is understandable since ‘he’ is really ‘me’. One who realises him will therefore be liked by all beings.
The Upaniṣad ends with the declaration that tapas (austerity), dama (self-control) and karma (works and duties ordained by the scriptures) are the means of attaining Brahman. So also a study of the Vedas and their subsidiary sciences and satya or truth.
And, one who realises Brahman by these means, gets rid of his sins and is established in ‘svargaloka’ (the world of Brahman).