Bhagavad Gita
1.36

तस्मान्नार्हा वयं हन्तुं धार्तराष्ट्रान्स्वबान्धवान् | स्वजनं हि कथं हत्वा सुखिनः स्याम माधव ||३६||

tasmān nārhā vayaṁ hantuṁ dhārtarāṣṭrān sva-bāndhavān sva-janaṁ hi kathaṁ hatvā sukhinaḥ syāma mādhava

Translation

Therefore we should not kill the sons of Dhritarashtra, who are our own kinsmen. How can we be happy by killing our own relatives, O Madhava?

Interpretation

Arjuna's conclusion: killing one's own kin cannot lead to happiness. He is applying a happiness-calculus to ethics. Krishna will reframe this entirely: happiness is not the criterion for right action — dharma is.