FWP:
This is a verse that the commentators generally adore. Not only is it extremely easy to paraphrase-- it almost doesn't need paraphrasing at all. The verse is virtually its own (prosy) paraphrase.
But it does offer one complexity: the idea of a ;hasrat 'of' uncommitted sins. Of course, this could well refer, as the commentators maintain, to the speaker's sadness at not being able to commit more sins-- either more in a general way (a larger number of the same kind), or more in a specific way (some particular sins, or particular kinds of sins). But couldn't there also be a more generalized burden or grief or regret occasioned just by the oppressive limitations of the human condition (so many sins, so little time!)?
Arshi is right that {79,2} is the perfect verse to compare it to. In both cases, I just can't share the commentators', and Faruqi's, enthusiasm. Like {79,2}, this verse seems excessively, even smugly, tidy and well-constructed. Perhaps this recoil on my part is just a quirk of my own temperament.
And here's a verse of Mir's that I don't much care about, for the same reasons: M{544,6}.
For another case study, compare the relatively tight, trim explicitness of this verse with the edgy, bleak, thrilling and chilling delights of {230,11}.
Tahira Naqvi, in our Urdu poetry group (Sept. 2023), came up with a strikingly reversed interpretation. Her reading is that the sinner or lover has directly challenged God, in a spirit of sheer (mischievous?) defiance: 'Well, if you're going to punish me for the sins I've committed, you can also punish me for the ones that I wanted to commit!'.
Hali:
That is, if we are definitely to be punished for those sins we committed, then we also ought to receive justice for those sins that because of lack of power we were unable to commit, and longing for which remained in the heart.
==Urdu text: Yadgar-e Ghalib, p. 126