S. R. Faruqi:

Here too the beauty of the implication has elevated the freshness of the theme, although its foundation is upon a commonplace word. The foundation of the verse is the word naz((a . That is, during the whole life there was no occasion for saying the 'circumstances of the heart', or it had no importance, or in one or another way he kept restraining himself, or he kept thinking that he would speak at the final time. Now when the final time had come, he realized that there was a great deal to say and absolutely no leisure. To call naz((a 'the space of a breath' is also fine.

The result, in any case, was that he was not able to express the circumstances of the heart. The aspect of failure is that the occasion which he had set aside for the expression of the circumstances-- that occasion proved insufficient to such an extent that it was as if it hadn't come at all. The meaning is also possible that in the state of naz((a what happens to the heart could have found a limited expression, but the circumstances were numerous and the leisure very little. In both kinds of themes there's a uniqueness/rarity.

It's also possible that through his whole life he kept on saying the circumstances of his heart (for example, in verses, or to people and to friends)-- to such an extent that his last breath arrived and even now the circumstances of his heart were many, he couldn't fully set out the circumstances of his heart: to whom he had kept saying them, or to whom he wanted to say them.

In the verse he's created a strangely Majnun-like mood of helplessness, as if he's kept on saying all this to himself alone. Or as though he considers his circumstances so important and uncommon that he can't be content until he's told them to others. There's a kind of compulsiveness that compels him to speak.

FWP:

SETS == EXCLAMATION
MOTIFS
NAMES
TERMS == IMPLICATION

Even in the last moments of his life, the speaker has apparently only one thought-- a passionate regret at his inability to express everything in his heart. The a;hvaal is plural; it's often used as though it were its singular form, ;haal , but here the plural sense works well to convey all the unexpressed, perhaps inexpressible, circumstances of the heart.

SRF teases out the main implications, and I would only add a few:

=That perhaps no one is listening at all, and he's talking to himself about these circumstances.

=That he's so far from expecting anything from the beloved that he not only doesn't send for her, he doesn't even think of sending for her.

=That perhaps it's not talking at all, but some other form of expression, that he would adopt, if only he had the time.

And as usual, the speaker's being ;hairaa;N means that it's left up to us to imagine both what kind of circumstances might have overtaken his heart, and what he would do about them if he could only have the time.

Note for grammar fans: In the second line a;hvaal is of course the plural of ;haal , but by convention it's treated as grammatically singular.