Katha Upanishad Verse 2.3.4
This verse stresses the critical importance of spiritual realization while still in the physical body. If one is able to know and realize the Brahman before the “falling of the body” (death), they transcend the need for further individual embodiment. However, failing to do so results in continued existence in the various “worlds of created things” as an embodied soul.
Sanskrit Verse
इह चेदशकद्बोद्धुं प्राक्शरीरस्य विस्रसः । ततः सर्गेषु लोकेषु शरीरत्वाय कल्पते ॥ ४ ॥
Transliteration
iha cedaśakadboddhuṃ prākśarīrasya visrasaḥ | tataḥ sargeṣu lokeṣu śarīratvāya kalpate || 4 ||
Translation
If here he is able to know before the falling of the body, then in the worlds of created things, he becomes embodied.

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