Bhagavad Gita 2.5
गुरूनहत्वा हि महानुभावान् श्रेयो भोक्तुं भैक्ष्यमपीह लोके। हत्वार्थकामांस्तु गुरूनिहैव भुञ्जीय भोगान् रुधिरप्रदिग्धान्।।2.5।।
gurūnahatvā hi mahānubhāvān śreyo bhoktuṃ bhaikṣyamapīha loke| hatvārthakāmāṃstu gurūnihaiva bhuñjīya bhogān rudhirapradigdhān||2.5||
gurunahatva hi mahanubhavan shreyo bhoktum bhaikshyamapiha loke hatvarthakamamstu gurunihaiva bhunjiya bhogan rudhirapradigdhan2.5
Meaning
Arjuna feels it would be better to live as a beggar than to enjoy wealth stained with the blood of his great teachers. Any pleasures won by killing them would be tainted with their blood.
महानुभाव गुरुजनों को न मारकर इस लोक में भिक्षा का अन्न भी खाना श्रेयस्कर है। गुरुजनों को मारकर उनके रक्त से सने भोगों को यहाँ भोगना उचित नहीं।
This is verse 5 of 72 in Chapter 2 (Sankhya Yoga) of the Bhagavad Gita.