S. R. Faruqi:

In this verse the phrase faẓl-e ilâhī is more valuable than a number of whole verses. If an equal to it is possible, then it's possible only in the second line's dil ko lagā hūñ . In faẓl-e ilâhī is both sarcasm about the arrangement made by the managers of fate and destiny, and also a distant glimmer of thankfulness, that without the Lord's grace such a history would not have been possible.

And how devastating will be the misfortune of that person for whom Divine grace would present itself in the form of the tearing apart of the breast! And how devastating will be a woundedness and helplessness such that one feels that he is doing himself mortal harm, but he can't stop that harm!

In the second line vaqt-e duʿā too is very fine. He hasn't made clear what the prayer would be for. Does the speaker wish to pray that he would even now be protected, and would stop doing himself mortal harm? Or does he wish to pray that just as through the Divine grace he has torn apart his breast, in the same way grace from on high would help him attain a state in which he would be able to rip his heart too into shreds? Or is it a matter of praying that when he is about to be finished off entirely, grace would now be vouchsafed to him? The ambiguity has created an extraordinary tension.

In dil ko lagā hūñ is such a powerful expression of the intensity of madness, the bending of the mind, a kind of mindless force and resolve to destroy oneself, that it makes one's hair stand on end. Such a verse can be created, even by the best of the best, only after years of work.

Qa'im has versified a similar theme, but his verse doesn't have the wild/savage absorption and sarcasm. Within its limits, Qa'im's verse, especially the second line, is very fine indeed:

garebāñ kī to qāʾim muddatoñ dhajjeñ uṛāʿī haiñ
yih ḳhāt̤ir jamʿa us din hove jab sīne ko ham chīreñ

[Qa'im, for ages we've been flinging around rags of our collar
this temperament of ours will be settled on that day when we would tear our breast]

One additional time Qa'im composed this theme. But this one doesn't have the idea that's in the previous one:

ṭuk garebāñ āj phaṭ kar dhajjiyeñ ho le to phair
chāk par sīne ke qāʾim pesh-dastī kījiʾe

[just wave around the rags of the torn collar, today
anticipate, Qa'im, the tearing of the breast]

FWP:

SETS
MOTIFS == CHAK-E GAREBAN; MADNESS
NAMES== GOD
TERMS == AMBIGUITY

That commonplace verb lagnā -- it's astonishing how many things it means (the definition above is just a small selection of the most appropriate parts of its range). But in this verse, its crucial last-moment position as the rhyme-word helps to augment its feeling of ominousness, of doom. The vision I have is that the speaker has 'attached himself to' the heart like a leech; it can never escape him. He will wrestle it into submission, gouge holes in it, and and finally tear it into bloody strips, just as he has already done to his breast.

If the speaker has clawed his breast into rags 'through Divine grace', probably he really thinks-- as a sign of his madness-- that the Lord has allowed him to perform this wild laceration, or even helped him to do it. And as SRF observes, in the second line 'it's time for prayer' could stand in a number of different relationships to the speaker's plan to start in on his heart. Prayer could be appropriate for someone who was about to die, or about to kill himself, or about to murder his helpless heart, or about to render up his spirit to God, or about to leave his loved ones forever.

The grim minimalism of the verse leaves us to decide all such possibilities for ourselves. The speaker is a madman in the process of killing himself-- and he obviously feels that God is on his side, or that he is on God's, every step of the way. It makes us wonder what God would have to say about that.