Apart from the theological hyperbole of the second line, the entire sher can also be seen as a flirting compliment to the earthly साकी who is passing the drinks around the mehfil... a sort of 'I'm a slave to you, you heavenly creature... just don't be miserly with the hooch!!'
Will someone tell me what these braided tresses are?!"
There goes Ghalib with his impossibly teasing word-play again...!! The object of his mischievous attention being the long braids that the Beloved wears her curls in...
The piquancy of the sher comes from the idiomatic use of कटना when used for a period of time, like the night. Idiomatically, शब् का कटना is the process of 'getting through the night'. But the literal meaning, of course, is to 'cut the night', which allows him to take teasing shots at the Beloved - namely, if one could cut her braids, they could be called the night, etc... the likening of them to snakes is also so visually evocative - braided long hair actually being rather serpentine in appearance, i mean!
तुम्हारी तर्ज़-ओ-रविश जानते हैं हम क्या है
रकीब पर है अगर लुत्फ़ तो सितम क्या है
"Your manner of behaving, I know (very) well
If it is grace/favours (that you're dispensing) to the Rakeeb, then what is oppression?"
Very sweet! This sher works (and works well!) in two quite distinct senses: in the first interpretation, it is an outright accusation directed at the Beloved - since she is perversely sadistic, even her deliberately brazen favours to the Raqeeb (as mentioned earlier, 'Raqeeb', like 'gair', 'dushman' and 'adu' is used to describe the poet's rival for the Beloved's affections) are actually aimed at tormenting the Poet (and not out of any genuine affection towards the Raqeeb). This is more or less the 'standard' politics of love, that has been the subject of commentary in virtually every tradition of poetry and prose... not much more that can be said about it.
In the other (and in my opinion, more delicious) interpretation, the Poet takes a sort of petty satisfaction in the thought that - knowing her unfaithful ways - the Beloved's apparent favours towards the Raqeeb will ultimately end up oppressing him in the same hell-fires that the Poet is currently burning in!
सुखन मे खामह-ए-गालिब की आतिश-अफ्शानी
यकीन है हम को भी, लेकिन अब उसमे दम क्या है
In (his) poetry, the scattering of fire by Ghalib's pen
I too believe (in it), but what life/strength now remains in it/him?"
Ha ha! Only someone as delightfully arrogant as Ghalib could so consistently come up with totally brilliant ways of praising himself!!
Just look at this gem of a maqta!! With a simple addition of a 'bhee', Ghalib attributes the fawning opinion (that his pen is filled not with ink, but with the fires of genius) to everybody but himself!! To which he, at best, humbly agrees!! And to compound the audaciousness, he goes on to wonder, with studied-innocence, whether his pen (or he himself) still continues to command the same strength of force that his interlocutors credit him with!!!! As he is well aware, the answer to that query is only too evident in the ghazal that has just been presented!!
आतिश-अफ्शानी !!! (to sprinkle fire) What a picturesque expression!