Reiterating the importance of self purification

The verse 5.25 emphasizes the spiritual enlightenment where ‘sages’ or ‘ṛṣayaḥ’ attain ‘brahmanirvāṇa’ or unity with the Ultimate Reality, Brahman. Shri Krishna speaks about individuals whose impurities and sins, ‘kṣīṇa kalmaṣāḥ,’ are completely eradicated. Only such purified individuals can truly comprehend their inherent nature.

Shri Krishna spoke about the need to get rid of impurities back in the beginning of the 2nd chapter: श्रीभगवानुवाच |

कुतस्त्वा कश्मलमिदं विषमे समुपस्थितम् |

अनार्यजुष्टमस्वर्ग्यमकीर्तिकरमर्जुन || 2||

śhrī bhagavān uvācha

kutastvā kaśhmalamidaṁ viṣhame samupasthitam

anārya-juṣhṭamaswargyam akīrti-karam arjuna

The Supreme Lord said: My dear Arjuna, from where have these impurities come upon your mind at this critical hour? It is not befitting an honorable person. It leads not to the higher abodes, but to disgrace.

When a person, through persistent meditation and control over their senses, manages to cleanse themselves of all the mental impurities and sins, they experience profound joy and realization of their true self. 

Another profound truth explained by Krishna is that enlightenment is not an escape from the world but a deeper engagement with it, driven by love and compassion and a sense of unity with all beings.