S. R. Faruqi:

;zaqan = a dimple in the chin

Usually ;zaqan is taken to mean 'chin', but it also refers to a dimple in the chin, or a dimple in the cheek caused by laughter-lines. In the present verse, Mir has used it with the meaning of 'cleft chin'. Urdu-knowers have imitated Persian-knowers in this usage; otherwise, unlike the situation among the Iranians and the Westerners, it used not to be considered any special sign of beauty.

The down on the cheek is called sabz ; with regard to this he has given to sabzah-e :xa:t the simile of bha;Ng [the marijuana-based drink, also called bhaa;Ng], because bhang too is green. The dimple/cleft in the chin is also called chaah-e ;zaqan ; thus the metaphor of 'well' and 'bhang' has been completed, and in this way an uncommon use of the idiom kuu;Nve;N bhaa;Ng pa;Rnaa has come to hand.

The meaning of kuu;Nv))e;N bhaa;Ng pa;Rnaa is 'for everybody in the neighborhood to go mad'. It's obvious that if bhang would fall into the well, then everybody in the neighborhood who drinks water from this well will lose his senses. The uncommon metaphorical use of the idiom is like this: that he would use the expression in the dictionary meaning, and its metaphorical meaning would also be present. If the idiom is taken in its dictionary meaning, then the metaphor, so to speak, becomes 'inverted' [maqluub]. This is the special style of Ghalib, Mir, and in Persian Bedil.

Atish has versified a theme similar to Mir's:

malaa;hat-e ;zaqan-e yaar kaa hai har suu shor
((ajiib lu:tf kaa khaarii hai yih ku;Nvaa;N niklaa

[the savoriness of the beloved's chin-dimple has created turmoil/brackishness in every direction
an extraordinarily pleasant salt has emerged from this well]

In Atish's verse the wordplay too is fine, but there's no 'proof' for keeping the malaa;hat limited only to the chin-dimple; thus the verse has become weak.

FWP:

SETS == IDIOMS
MOTIFS == [BELOVED IS A BOY]
NAMES
TERMS == METAPHOR; PROOF

The enjoyable play on idioms depends on the way Urdu uses chaah , meaning 'well' (for drawing water), metaphorically for what we call a 'dimple'. Once the beloved has a 'well' on his chin, the rest of the verse follows beautifully, for he also has 'greenery' on his face in the form of the down on his cheeks. Since that 'greenery' seems to have fallen into the 'well' too-- perhaps it's really bhang? That would explain the way all the beholders are driven mad by the beloved's beauty, as if they'd been drinking water from a well full of bhang.

Note for script fans: The various spellings of what in my view ought to be ku;Nve;N , scanned short-long, are enough to drive anyone crazy even without the bhang. I don't like the extra )) that the kulliyat inserts, but I've reproduced it just to show my respect for the editors. (In quoting Atish's verse, SSA writes ku;Nvaa;N , which to my mind is much better.) But I think the kulliyat is trying to make the vaa))o have a long 'uu' sound, and that's why it then requires the hamzah. But of course that first syllable then has to be arbitrarily shortened, since otherwise it should be metrically long. Whereas my spelling has no anomalies, and in pronunciation would be basically indistinguishable from that of the kulliyat. But never mind, we are used to anomalies and can go with the flow.