Bhagavad Gita · Chapter 2: The Path of Understanding
Bhagavad Gita 2.26
अथ चैनं नित्यजातं नित्यं वा मन्यसे मृतम् ।
तथापि त्वं महाबाहो नैवं शोचितुमर्हसि ॥
atha cainaṃ nityajātaṃ nityaṃ vā manyase mṛtam | tathāpi tvaṃ mahābāho naivaṃ śocitumarhasi ||
And even if you think of it as constantly being born and constantly dying, even then, mighty-armed Arjuna, you should not grieve like this.
Modern context
Krishna now argues from the opposite assumption. Suppose there is no eternal self, and a person simply is born and dies. Even so, he says, this grief is not warranted. He does not demand that Arjuna accept his metaphysics first. A good argument meets people where they stand.