Bhagavad Gita 18.72
O Arjuna, have you listened attentively to My words? Has your ignorance and delusion gone?
कच्चिदेतच्छ्रुतं पार्थ त्वयैकाग्रेण चेतसा।कच्चिदज्ञानसंमोहः प्रनष्टस्ते धनञ्जय॥kaccidetacchrutaṃ pārtha tvayaikāgreṇa cetasā|kaccidajñānasaṃmohaḥ pranaṣṭaste dhanañjaya||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).