Beings such as sons and friends, which are aggregates of effect and instrument, are unseen at first; that unseen state is their beginning. Having arisen, and before death, they are manifest in the middle; and at the end they have the unseen again for their close, passing once more, after death, into the unmanifest. As it has been said, 'come into sight from out of sight, and gone again to the unseen; he is not yours, nor you his; what then is this vain lament?' What lament, what babbling, can there be over beings that are, before and after, a mere apparition between the unseen and the unseen? This Self is hard to know. Why, then, do I reproach you alone, when the cause of the error is common to all? And why is the Self so hard to know? He says.

Beings such as men are existent substances; with their prior state unapprehended, their middle state, manhood and the rest, apprehended, and their later state unapprehended, they abide in their own natures. So there is here no occasion for lament. Having said that, even on the doctrine that the body is the self, there is no occasion for grief, the Lord now says that, in regard to the self distinct from the body, of a marvellous nature, a seer, a speaker, and a hearer, and one whose certainty about the self comes from hearing, are all hard to find.

This is a brief sub-gloss. For a fuller reading of this verse, see Madhusūdana, Śaṅkara, or Rāmānuja above.

Krishna makes this very point clear with 'beings are unmanifest in their beginnings'.