S. R. Faruqi:

Usually they say aafat kaa parkaalah [spark of disaster], but with regard to the affinity, he said aag kaa parkaalah [spark of fire]. The meaning of garmii chashm rakkhe is garmii kii ummiid rakkhe , with the kii omitted. The omission of the izafat [i.zaafat kaa ;hazaf] is common in Persian and abnormal in Urdu. But in Ghalib and Mir, there are examples of it.

[See also {352,7}.]

FWP:

SETS == IDIOMS
MOTIFS == EYES
NAMES
TERMS == IZAFAT

The eye imagery of inti:zaar karnaa ('to wait', based on 'to look out for') is here echoed in the sense of kii chashm rakhnaa , 'to keep an eye out for'; SRF ascribes to it an overtone of hopeful, rather than merely neutral, waiting. Someone may 'keep an eye out' in hope for heat from that spark of fire, only when he would set fire to his whole body and mind, as I have done. That 'spark of fire' may be the mischievous beloved, who is the 'spark of disaster' [aafat kaa parkaalah] of the usual idiom (here enjoyably altered); or perhaps a kind of metaphorical, late-stage fire of passion like that envisioned in

{15,3}.

In either case, the verse turns on the pivot of tab , which is perfectly positioned to mean 'then', and of course also means 'heat', as in

{15,1}.

Why merii :tara;h se ? If it's taken merely to mean 'as I have done', then it adds nothing to the verse and almost looks like padding. But if we take it more seriously, then the verse claims that it's necessary not just to burn up one's whole body and mind, but to do it in one particular way, 'in my style/manner'. Of course, it's left to us to decide what this style/manner might be.

Note for meter fans: It's necessary to read rakkhe , with a tashdiid , to make the line scan; this kind of optional doubling in the perfect is relatively common. Also, notice that :tar;h can also be scanned as :tara;h ; this scansion is in fact very common.