Bhagavad Gita 1.37
तस्मान्नार्हा वयं हन्तुं धार्तराष्ट्रान्स्वबान्धवान्। स्वजनं हि कथं हत्वा सुखिनः स्याम माधव।।1.37।।
tasmānnārhā vayaṃ hantuṃ dhārtarāṣṭrānsvabāndhavān| svajanaṃ hi kathaṃ hatvā sukhinaḥ syāma mādhava||1.37||
tasmannarha vayam hantum dhartarashtransvabandhavan svajanam hi katham hatva sukhinah syama madhava1.37
Meaning
Therefore, Arjuna concludes, it is not right for them to kill their own relatives. How could they be happy after destroying their own kinsmen?
इसलिए हे माधव! हम अपने बन्धु धृतराष्ट्र के पुत्रों को मारने के योग्य नहीं हैं। अपने ही स्वजनों को मारकर हम कैसे सुखी हो सकते हैं?
This is verse 37 of 47 in Chapter 1 (Arjuna Vishada Yoga) of the Bhagavad Gita.