bah qadr-e ;hasrat-e dil chaahiye
;zauq-e ma((aa.sii bhii
bharuu;N yak goshah-e daaman gar aab-e haft daryaa ho
1) according to the longing/regret/grief of the heart ought
to be the relish/pleasure of sins too
2) I would fill a single corner of my garment-hem, if there would be the
water of seven seas
;hasrat : 'Grief, regret, intense grief or sorrow; --longing, desire'. (Platts p.477)
;zauq : 'Taste, enjoyment, delight, joy, pleasure, voluptuousness'. (Platts p.578)
ma((aa.sii : 'Acts of disobedience, sins, crimes'. (Platts p.1046)
The relish for sin too ought to be equal to the longing/regret of the heart. I would wet one corner of my garment-hem, if I would have the water of seven seas. (178)
However many sins I vainly long for, in exactly that many sins there is a relish too.... That is, however many kinds of sins there are, they can't satisfy the longing/regret of my heart. (234)
As Arshi points out, {38,6} is indeed a perfect companion piece for this one. But this one is the more complex of the two, because it also introduces a kind of balancing between sins and longings that plays no part in {38,6} (which is however, in its own terms, a real gem).
This verse in fact has a first line that seems to encapsulate the thought of {79,2}. There too, the number of vain longings [;hasrat] is correlated with the number of sins. But that one is talking specifically to the Lord, and this one seems to be a soliloquy on the 'longings = pleasures/sins' equation.
Which raises the question of why this equation should be made in the first place. Are my longings perhaps sins in themselves, or for sinful things? That would make the equation very tidy. Otherwise, the only reason for the equation is an eyeball-to-eyeball confrontation with God, the kind in which Iqbal specializes-- and the kind laid out in {79,2}. 'God, you've caused me X amount of suffering (through vain longings etc.), I've committed X amount of sin; shall we call it even?'
In any case, I ought to commit-- and proportionately relish committing-- as many sins as I have painful longings and sorrows. And my longings, sorrows, griefs are so innumerable that if I converted them all into an equal amount of (relish of) sinning, I would sin so much that all the water in all the seven seas could barely do more than wet the corner of my garment-hem. It wouldn't even suffice for actual 'sinfulness'-- tar-daamanii , literally 'wet-skirtedness'-- at all.
Underneath it all, the verse is not really so much about sins; the sins are mostly pressed into service as a colorful, eye-catching metaphor. The verse, like the lover's life, is about longings (including the longing for sins), and about their inexhaustibility, insatiability, incommensurability with anything else we can find to measure them against. Really the one that wraps it all up is {219,1}.
Nazm:
It's a term in Persian, that they call a sinner a 'wet-skirted one' [tar-daaman]. And 'the water of seven seas' he has made a metaphor for an abundance of sin. (126)
== Nazm page 126