Sri Aurobindo translates Mundaka Upanishad, Chapter 3, Section 2, Verse 1: “He knows this supreme Brahman as the highest abiding place in which shines out, inset, the radiant world. The wise who are without desire and worship the Spirit pass beyond this sperm. (Shankara takes it so in the sense of semen virile, which is the cause of birth into the cosmos. But it is possible that it means rather ‘pass beyond this brilliant universe’, the radiant world which has just been spoken of, to the greater Light which is its abiding place and source, the supreme Brahman.)”
This final section of the Mundaka Upanishad shifts the focus to the psychological texture of the seeker who wishes to shift from the individual to the divine standpoint. The focus here, starting with this verse, is on the relationship of the vital desires to the realisation of the Supreme Brahman. Previous segments have developed the understanding of the nature of the Brahman and the relation of the Brahman to the manifested universe, as well as the preparation of the individual seeker for the transition through various yogic processes, including gaining control over the breath, stilling the mind-stuff and attaining a state of reflective, joyful serenity. The ultimate answer is to overcome the promptings of desire at the individual level which cause us to remain fixated in the individual standpoint, seeing and acting from that view. The Taittiriya Upanishad in its famous “calculus of bliss” passage makes essentially the same point, that overcoming the force of desire is the key to the indescribable bliss of the highest states of awareness.
Just as individual desire anchors the consciousness in the individual standpoint, releasing the hold of desire and shifting the focus to the Supreme is a necessary basis for the shift to a new standpoint that is unified with the Brahman and the significance of its manifestation. Some people interpret this to mean suppression of desire, but suppression is essentially equivalent, from a psychological viewpoint, to fulfillment of desire. In both cases, the focus is on the desire and its impulsion. The solution lies in a shift of focus and non-attachment to desire or specific fruits of action, as has been explained at some great length in the Bhagavad Gita. Some believe that desire is necessary as the wellspring of action in the world. Without desire, they say, there is no motivation to act. This led eventually to the conclusion that one should renounce the life in the world and somehow thereby overcome desire to achieve oneness with Brahman. Yet it is possible to act in the world, under the impulsion of the divine force and its intention in the manifestation, without the attachment to personal fulfillment of desire or specific fruits of the action. The Mundaka Upanishad hints at what turns into an extensive review of applied psychology as a yogic procedure in the Gita. Sri Aurobindo in Bhagavad Gita and Its Message, as well as in Essays on the Gita, has explored these issues at great length, so rather than repeat them, we refer to those texts.
Sri Aurobindo, The Upanishads, Mundaka Upanishad, pp. 193-210