FWP:
SETS == WORDPLAY
SPEAKING: {14,4}
SWORD: {1,3}
For background see S. R. Faruqi's choices. For more on Ghalib's unpublished verses, see the discussion in {4,8x}.
At the heart of this verse, as of so many, is wordplay involving the spectacularly protean little word aab . For discussion and more examples, see {193,2}. Here's how it pulls the wordplay together:
=as water: 'greenery' (verdant foliage) requires water; 'tongues' require water; 'swords' require water in their forging
=as sharpness or shiningness or temperedness: all qualities of a 'sword' (or many swords), carried in 'one hand'
=as an element in 'poison-water': this water can be 'dirty' (like the nasty tongues) or 'stagnant' (stagnant water turns green) or 'envenomed' (poison is easily mixed into water); according to Gyan Chand, poison is also conventionally thought to be 'green'.
Gyan Chand suggests that the swords were quenched [bujhnaa] in zahr-aab during the forging process, and that this has turned them green. Such a color-change doesn't sound likely. But swords could certainly also be dipped in a poisonous liquid, to make any small scratch from them deadly (think of Hamlet's death). A striking way to describe a poisonous tongue, isn't it? It doubles the sarcastic effect of ((aziizaan in the first line.
Compare {217,2}, another verse about swords and zahr-aab . The possibility that zahr-aab could also refer to an acidic chemical used in the sword-tempering process is discussed in the context of that verse.
Asi:
As someone has taken a sword quenched in the greenery of zahr-aab , it's apparent that the leaves of greenery and grass have a similitude with a sword. Thus our bad-speaking esteemed one too has taken up, for our slaying, thousands of swords that she has quenched in zahr-aab .
== Asi, p. 171