1. Urdu poetry is often written not directly, but in a round about way, by allusions, hints, indications and suggestions. It often has a superficial, literal, outer meaning, and an inner, deeper, real meaning, to understand which one has to wrack one's brains.
2. Great Urdu poets like Ghalib believed that poetry should not be written in the language of the common man, and they had a horror of the commonplace. To make it dignified and sophisticated (andaaz-e-bayaan) they often used Persian expressions and metaphors.
3. To properly understand the poem one has to see the historical context. For example, the poem in question was written by Faiz when he was in jail, accused in the Rawalpindi conspiracy case, for which he could have even be hanged. Hence he could not criticise the government directly, but had to use very guarded, indirect language while writing the poem, like Maxim Gorky's 'Song of the Stormy Petrel' which was written in 1901 when Russia was under the autocratic Czarist rule, and it was dangerous to use direct language.
Now let me explain the real meaning of the poem, sher (couplet) by sher.
1. Gulon mein rang bhare baad-e-naubahaar chale
Chale bhi ao ki gulshan ka kaarobaar chale
Now the literal, outer, superficial meaning of the sher is this :
"Among the flowers a colourful breeze of the new spring is blowing
Come, so that the work of the garden can be done"
So, literally it seems to be a call to a lover.
But that is not what Faiz is really conveying. The word 'gulshan' (garden) is not to be understood literally. It means the country.
The first 'misra' (line) really means that the objective situation in the country is ripe for a revolution. The second misra is a call to patriots and revolutionaries to come forward and fight for the country, which is in great distress.
2. Qafas udaas hai yaaron saba se kuch to kaho
Kaheen to beher-e-khuda aaj zikr-e-yaar chale
The literal meaning of this is:
“The prison is sad, friends, say something to the morning breeze
For God’s sake at least somewhere there should be mention of one’s beloved"
The real meaning here is that the whole country has become a qafas (prison).
The word ‘yaar’ (beloved) used here really means the people, not just one person.
So the poet is calling upon patriots to step forward and fight for the people, since the whole country has become a jail (which Pakistan had become under martial law).
3. Kabhi to subeh tere kunj-e-lab se ho aaghaaz
Kabhi to shab sar-e-kaakul se mushkbaar chale
The literal meaning of this is:
“At least sometimes let the morning start from the corner of your lips
At least sometimes in the night your tresses be filled with a scent like musk"
But what the poet is really conveying is that at least sometimes the people should think of the country, not just of oneself.
4. “Jo hum pe guzri so guzri magar shab-e-hijraan
Hamaare ashk teri aaqabat sanwaar chale"
This literally literally means:
"Whatever befell me befell me, but on the night of separation
My tears adorned your future"
The real meaning here is that the poet is thinking of a patriot’s death, when he will be separated from the people, his real lover. He says that though he will be no more, his struggles will have helped their cause.
5. Maqaam Faiz raah mein koi jacha hi nahi
Jo koo-e-yaar se nikle, soo-e-daar chale
This literally means :
“I could not on my route find any place where I could settle down
When I left the street of my beloved, I went to the gallows"
But what the poet is really conveying is the difficult, formidable and Herculean journey of the revolutionary, who after serving his beloved (the people) often ends up on the gallows.