The Jiva, the individualised ignorance, is the participant of the fruits of action, of right and wrong, of good and evil; the Jiva forges bondage through egoism and loosens the bonds through Buddhi, the counter force of ignorance. Realise that all is won the moment the indriyas (external and internal) are put out of action.
Discard them as false and misleading; merge them all in the Manas. Throw the Manas back into the Buddhi and the Buddhi or individualised intelligence into the cosmic intelligence of Hiranyagarbha. And, having reached that stage of Sadhana, merge the cosmic intelligence in the Atmatattva of which it is but a manifestation. Then you attain the stage of Nirvikalpa Samadhi, the perfect unruffled equanimity of Absolute Oneness which is your true nature. That is the secret propounded by this Upanishad; that and the fact that all Creation is a proliferation of Nama (name) and Rupa (form). (UV, p. 22)