FWP:
SETS
CANDLE: {39,1}
GATHERINGS: {6,3}
For background see S. R. Faruqi's choices. This verse is NOT one of his choices; for the sake of completeness (since it's the only unpublished verse in this ghazal), I have added it myself. For more on Ghalib's unpublished verses, see the discussion in {4,8x}.
The first line, in proper mushairah performance style, is tantalizingly complex and incomplete. For why should there be such a thing as a 'desolation-chamber of a gathering'? After all, the qualities of va;hshat -- desolation, loneliness, dreariness, wildness, barbarism, horror, madness (see the definition above)-- are entirely the opposite of the qualities of a bazm or gathering, which include companionship, civilized behavior, sophistication, the enjoyment of beautiful people and elegant attire, decorations, food and drink, music, perfumes, poetry.
Only after hearing the second line can these two settings be fully appreciated. In whatever situation the speaker found himself he, like a candle, considered his basic stock in trade, his essential property (with a nice little wordplay on 'head'), to be the flame of passion. And really, in both of those settings a candle-flame (or a candle-flame-like flame of passion) is equally crucial. In a state of desolation, dreariness, wildness, horror, madness [va;hshat], the symbolic and/or literal power of a lighted candle would make all the difference to one's chances of survival. And in a gathering, not only is the candle a symbol of brightness, illumination, and joy, but it's also the uniquely potent (and passionately self-consuming) emblem of the transitoriness of exactly such gatherings (as most beautifully in {169,12}.
There's also the piquancy of amalgamating these two seemingly opposite environments: the speaker experiences the 'gathering of the world' as a 'desolation-chamber'. Thanks to the flexibility of the i.zaafat , we can't tell whether the gathering of the world itself takes place in a 'desolation-chamber', or whether it owns or is linked to a related 'desolation-chamber' of some kind (an isolation cell for madmen?). Nor can we tell whether the speaker's description applies only to himself (everybody else enjoyed the gathering, but he experienced it as a chamber of horrors), or offers a general description of life in the world (it seems to be glittering and enjoyable, but in truth it's a nightmare of desolation).
The verb samajhnaa can mean not only 'to understand' (accurately), but also 'to consider' (subjectively, perhaps inaccurately); on this see {90,3}.
Zamin:
The poet says, 'When I came from the radiant [Sufistic] 'World of Spirits' to the dark 'World of Bodies', then I found that house to be a pitch-black desolation-chamber and I needed light. Where would I have found a lamp, a wick, oil? I found that the simplest thing was to use the flame of passion as the flame of a candle. That is, to set fire to the harvest of my existence. The gist is that in order to find a refuge from disgusting things, he leaped into the fire of passion.
== Zamin, p. 54