तमुवाच हृषीकेशः प्रहसन्निव भारत।सेनयोरुभयोर्मध्ये विषीदन्तमिदं वचः॥
tam-uvāca hṛṣīkeśaḥ prahasanniva bhāratasenayorubhayor-madhye viṣīdantam-idaṃ vacaḥ
Word by word
The verse says
Sanjaya said: Then, between the two armies, Krishna spoke to the grief-stricken man — and as he began, he was almost smiling.
In plain words
Krishna smiles.
His friend is broken, sitting in a chariot between two armies, and the text says he spoke prahasan iva — as if smiling, or with the beginning of a smile.
It is one of the strangest details in the book, and everything about how you read the next seventeen chapters depends on what you make of it.
Where you've felt this · in growing older
A doctor who has seen your particular fear a thousand times does not look worried when you describe it. That steadiness is not indifference. It is the only information you actually needed.
Going deeper
Why smile at a man in this state?
Not mockery. Nothing else Krishna does supports that reading. The smile is the first piece of information he gives Arjuna, and it comes before a single word: this is not what you think it is.
Arjuna is experiencing the end of the world. Krishna is looking at something he can see the whole shape of. The gap between those two positions is the gap the teaching has to cross, and the smile is the first sign that such a gap exists.
The little word iva — as if — matters too. Not a broad smile. The suggestion of one. The poem is careful not to make him callous.
And notice where this happens: senayor ubhayor madhye, between the two armies. The exact phrase from Chapter 1. Nothing about the situation has improved. Nobody has withdrawn. The teaching begins in the worst available place, and it begins with a man who is not frightened by it.