Mundaka Upanishad 3.2.4

नायमात्मा बलहीनेन लभ्यो
न च प्रमादात् तपसो वाप्यलिङ्गात् ।
एतैरुपायैर्यतते यस्तु विद्वां-
स्तस्यैष आत्मा विशते ब्रह्मधाम ॥ ४॥

nāyamātmā balahīnena labhyo
na ca pramādāt tapaso vāpyaliṅgāt .
etairupāyairyatate yastu vidvāṃ-
stasyaiṣa ātmā viśate brahmadhāma .. 4..

This Atman cannot be attained by one who is without strength or earnestness or who is without knowledge accompanied by renunciation. But if a wise man strives by means of these aids, his soul enters the Abode of Brahman.

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