fikr-e su;xan yak-inshaa zindaanii-e ;xamoshii
duud-e chiraa;G goyaa zanjiir-e be-.sadaa hai
1) the thought/imagination of poetry/speech is wholly/'one-creation' a prisoner of silence
2) the smoke of the lamp is, {so to speak / 'speaking'}, a chain/fetter without a voice/sound
fikr : 'Thought, consideration, reflection; deliberation, opinion, notion, idea, imagination, conceit; counsel, advice; care, concern, solicitude, anxiety, grief, sorrow'. (Platts p.783)
inshaa : 'Creating, producing, composing; writing, composition; style, elegance of style, especially in letter-writing; the belles lettres'. (Steingass p.111)
.sadaa : 'Echo; sound, noise; voice, tone, cry, call'. (Platts p.743)
Thought about poetry is a kind of creation on which is the chain/fetter of silence. If we take the meaning of inshaa to be 'creation', then we can say that thought about poetry is a kind of creative work that is done in silence. Thought about poetry is done at night, after lighting a lamp. In this way the smoke of the lamp is a symbol of thought about poetry. The smoke of the lamp has a similitude with a chain/fetter, but with a voiceless/soundless fetter, because in the act of creating poetry there's no voice.
SETS == MULTIVALENT WORDS ( goyaa ); POETRY
BONDAGE: {1,5}
SPEAKING: {14,4}
For more on Ghalib's unpublished verses, see the discussion in {4,8x}. See also the overview index.
The adverbial phrase yak-inshaa belongs to a group of expressions compounded with yak -- for more on these, see {11,1}-- of which Ghalib was particularly fond. They are idiomatic in Persian, but not in Urdu-- which is probably why Zamin explains the phrase in implausibly literal terms ('for as long as it takes to compose a literary work').
But really the chief charm of the verse is its pervasive imagery about poetic 'speech': su;xan , inshaa , ;xamoshii , goyaa , be-.sadaa . The focal point is goyaa -- it's located in the emphatic position right before the caesura, and has the colloquial meaning of 'as if' or 'so to speak', as well as the literal meaning of 'speaking' (for more on this see {5,1}).
Silence is opposed to 'speech', but silence is also indispensable for the creative 'thought, reflection' through which poetry/'speech' comes into being. This somewhat paradoxical claim is echoed in the second line: the smoke of the oil lamp is a powerful 'chain' that confines the poet within the solitary cell of his mind-- a chain that in some sense 'speaks', but is also 'without a voice, sound' (whereas a madman's chains are always clanking and rattling).
The smoke of an oil lamp is also used to make collyrium, which in the ghazal world is well known to be an enemy of the voice; on this see {44,1}.
Compare the lovely {33,4}, in which the poet is an 'opium-addict of the smoke of the lamp'.
Zamin:
yak-inshaa = That is, according to one composition; that is, as long as the time in which one verse or one nazm would be composed/'said', or one prose piece would be written-- for that long thought and poetry remain captive in the prisonl of silence. And the chains/fetters on their feet are the smoke of the lamp-- and they too are without a voice/sound. Thus this prison is the prison of silence. The gist is that silence is necessary for thought and poetry/speech.
== Zamin, p. 409