अव्यक्तादीनि भूतानि व्यक्तमध्यानि भारत।अव्यक्तनिधनान्येव तत्र का परिदेवना॥
avyaktādīni bhūtāni vyakta-madhyāni bhārataavyakta-nidhanānyeva tatra kā paridevanā
Word by word
The verse says
Beings are unseen before they begin, seen in the middle, and unseen again at the end. Why grieve over that?
In plain words
A picture rather than an argument.
Every person is unseen, then seen, then unseen. You only ever meet anyone in the middle stretch.
And then the flat question at the end. Not a rebuke exactly. Just: what is it, in that, that you are grieving over?
Where you've felt this · in community
You sit next to Farida for four years and know her Monday mood and her daughter's name. Then she moves to Chennai and you never speak again. She existed before you met and she carries on afterwards. What you had was a section, never the whole.
Going deeper
Krishna is not saying that people come from nothing and go back to nothing. He is saying they come from what is not displayed, appear for a while, and return to what is not displayed.
The word is avyakta - unmanifest, not shown - and it is not the same as non-existent. That difference carries the whole verse.
It is a strange thought to sit with, and it is meant to be sat with rather than solved. The middle stretch - the only part of anyone you have ever seen, including yourself - is being presented as the exception rather than the rule.
Notice that the closing question, kā paridevanā, what lamentation, is left genuinely open. It is not answered. The chapter simply moves on and the reader is left holding it.
That is deliberate. Some questions do more work unanswered, and this is one you may find yourself carrying around for a while.