Chapter-18, Verse 48

Ashtavakra Gita Verse 18.48 

वस्तुश्रवणमात्रेण शुद्धबुद्धिर्निराकुलः ।

नैवाचारमनाचारमौदास्यं वा प्रपश्यति ॥ ४८ ॥

He whose mind is Pure and undistracted from the simple hearing of the Truth, the wise one, no more sees what is proper and improper action or even what is inaction. 

The meaning of this verse is that the one who has attained the clear and Pure understanding of the Ultimate Reality (vastu) by merely listening to the teachings of the scriptures or the Guru, does not see any difference between right and wrong actions, or between attachment and detachment. He is free from all dualities and conflicts, and remains in a state of peace and bliss. He does not need to perform any rituals, duties, or practices to attain Realization, as he has already Realized his true nature as the witness of everything.

This verse expresses the essence of the Advaita Vedanta philosophy, which asserts that the Self (atman) is identical with the Supreme Reality (brahman), and that the apparent multiplicity and diversity of the world is due to ignorance 

(avidya) of this Truth. The only way to overcome this ignorance is to gain the direct and immediate Knowledge (jnana) of the non-dual reality, which is possible by the Grace of the Guru and the scriptures. Once this Knowledge is attained, the seeker becomes free from all bondage and suffering, and enjoys the supreme bliss of the self.

Similar verses from other Vedic texts, which also expound the same theme are:

- Mundaka Upanishad

ब्रह्मैवेदममृतं पुरस्तात् ब्रह्म पश्चात् ब्रह्म दक्षिणतश्चोत्तरेण । अधश्चोर्ध्वं च प्रसृतं ब्रह्मैवेदं विश्वमिदं वरिष्ठम् ॥

Brahman is this immortal, before us, behind us, to the south and to the north, below and above, extended everywhere. Indeed, this whole universe is the Supreme Brahman. 

This verse is from the Mundaka Upanishad, one of the principal Upanishads, which are the ancient scriptures that reveal the highest knowledge of the Self and Brahman. The verse declares that Brahman, the Absolute Reality, is the source, sustenance, and dissolution of everything that exists, and that there is nothing apart from it. The verse also affirms that Brahman is immortal, infinite, and Supreme, and that the seeker should realize his identity with it.