वेदाविनाशिनं नित्यं य एनमजमव्ययम्। कथं स पुरुषः पार्थ कं घातयति हन्ति कम् ॥

vedāvināśhinaṁ nityaṁ ya enam ajam avyayam kathaṁ sa puruṣhaḥ pārtha kaṁ ghātayati hanti kam

Who knoweth him indestructible, perpetual, unborn, undiminishing, how can that man slay, O Pârtha, or cause to be slain?

In plain words: Krishna calls Arjuna "Partha," son of Pritha. He asks how a person who knows the soul is eternal and unborn could truly kill anyone or make anyone be killed.