S. R. Faruqi:

He has put into the verse an extraordinary kind of 'implication'. One interpretation is that the beloved formerly made a show of affection toward us, then she left us and ensnared other lovers. But from 'in grief' the suggestion also emerges that the beloved is now not in this world. Or even if she is, then she's left them all and hidden herself somewhere.

FWP:

SETS
MOTIFS == SOUND EFFECTS
NAMES
TERMS == IMPLICATION

The verse makes a fine show of triple internal rhyme: the same rhyme appears at both the halfway point and the end of the first line, and at the halfway point of the second line. Which is basically all there's room for, since the end of the second line is already determined. The effect can hardly help but be cumulative-- and indeed, the semantic shape of the verse works that way too, for the halfway point of the second line marks the end of the identification of the person being discussed, leaving the second half of the second line for conveying information about that person.

The structure of kisii se yaar honaa looks unusually mutual, and even strikingly transactional, when compared to kisii kaa yaar honaa , the usual phrase. And of course, yaar also echoes dost in the first line. Is the old lover boasting about the access he used to enjoy? Is he urging later lovers to be warned by his example? Or is he just indulging in a bit of nostalgic reminiscence? As so often, the tone is left up to us to decide.