S. R. Faruqi:

Mir was so fond of this theme that he went on versifying it in various ways till the end of his life. In addition to the present verse, he has used this theme clearly in a number of other verses. But the intensity and terrifyingness and cold tone of the [Persian] verse of Naziri from which he had borrowed it-- not even Mir was able to attain that:

'Not to speak of feather and wing, its head and beak are cut off,
If any bird from this branch would lift its voice.'

The 'miracle of expression' [ějāz-e bayān] in that verse is also devastating. Now consider Mir's verses. From the first divan [{347,6}]:

chhūṭnā mumkin nahīñ apnā qafas kī qaid se
murġh-e ser-āhang ko koʾī rihā kartā nahīñ

[my release is not possible, from the imprisonment of the cage
a bird full of song, no one frees]

From the first divan [{432,2}]:

chhūṭnā kab hai asīr-e ḳhvush-zabāñ
jīte-jī apnī rihāʾī ho chukī

[when does a sweet-tongued prisoner get released?
as long as I live, my release?-- it's done with!]

From the second divan [{749,9}]:

mīr ai kāsh zabāñ band rakhā karte ham
ṣubḥ ke bolne ne ham ko giriftār kiyā

[Mir, if only we always kept our tongue silent!
the morning's speech made us captive]

From the second divan [{799,9}]:

asīr mīr nah hote agar zabāñ rahtī
huʾī hamārī yih ḳhvush-ḳhvānī-e saḥar ṣaiyād

[Mir, we would not be a captive, if the tongue had remained [silent]
this good-voicedness of ours at dawn became a Hunter]

From the third divan [{1065,4}]:

asīrī kā detā hai muzhdah mujhe
mirā zamzamah gāh-o-be-gāh kā

[it gives me the good-news of captivity,
my singing at suitable and unsuitable times]

From the fourth divan [in Persian]:

'Oh Mir, if only I had kept my tongue inside my mouth!
Finally this dawn-singing caused me to be captured.'

From the fourth divan [{1345,3}]:

ḳhvush-zamzamah t̤ayūr hī hote haiñ mīr asīr
ham par sitam yih ṣubḥ kī faryād se huʾā

[only/emphatically sweet-singing birds are prisoners, Mir,
this tyranny came upon us from the lament at dawn]

From the fourth divan [{1451,2}]:

zabāñ se hamārī hai ṣaiyād ḳhvush
hameñ ab ummīd-e rihāʾī nahīñ

[the Hunter is pleased with our tongue
now we have no hope of release]

From the fifth divan [{1734,6}]:

rihāʾī apnī hai dushvār kab ṣaiyād chhoṛe hai
asīr-e dām ho t̤āʾir jo ḳhvush-āvāz ātā hai

[my release is difficult-- when does the Hunter release
that bird, imprisoned in the net, who seems to be sweet-voiced?]

In {799,9} the sense of zabāñ rahtī as zabāñ band ho jātī is very fine. In {1345,3} a small point is that we weren't a sweet singer, we used to complain at/to the dawn, even so we were captured. In addition to these points, there's nothing special in any of the verses.

Rather, Dagh has made off with Mir's theme and, in his 'feminine' [begamātī] style, versified it well:

ḳhvush-navāʾī ne rakhā ham ko asīr-e ṣaiyād
ham se achchhe rahe ṣadqe meñ utarne vale

[sweet-voicedness kept us a captive of the Hunter
better ones than we were sacrificed [to ward off evil]]

But since in Naziri's verse the theme has greatly advanced from this point (that the bird is a captive because of its sweet singing)-- or rather, since by bringing the matter to murder and martyrdom he has changed the substance of the theme, it's thus possible that instead of following Naziri, Mir might have profited from this [Persian] quatrain of Baba Afzal Kashi:

'Oh excellently-singing Nightingale, what a sweet voice you have!
You're intoxicated, and a captive of desire [for freedom].
But I'm afraid you'll never reach your dear friends,
Because you're caged due to your tongue itself.'

In Baba Afzal's quatrain the wordplay and meaning-play are worthy of praise; his theme too is very close to Mir's. In Mir's present verse ham-ṣafīr too is not devoid of pleasure. Because in the second line the ham , the threat of whose capture has been expressed, can be the speaker and his 'fellow-warbler' both, or else only the speaker. In the second situation, the speaker is alone in his bad predicament. In the first situation, it's the flock of sweet singers, or at least a pair, who are about to be captured.

The tone is absolutely cool and free of self-pity. In the destiny of an artist is a kind of sadness, or unsuccess, or constraint. Of however high an order the artist may be, to that extent he'll be melancholy; this distress has been expressed with great excellence. Whether this melancholy would be because of captivity, or because of death, or because of being deprived of freedom, it is in any case present in the artist's portion.

FWP:

SETS == POETRY
MOTIFS == BONDAGE; [LOVER AS BIRD]
NAMES
TERMS == THEME

'If this is singing...' sounds in English like the beginning of an insult ('...then I could be an opera star!'). But in Urdu, it sounds like a very strong boast: 'this is how real singing should be done!'. And who better to illustrate the point than Ghalib? Boasting about a newly-composed ghazal, he writes, 'Brother! For the Lord’s sake, do this ghazal justice! If this is Rekhtah, then what did Mir and Mirza [Sauda] compose? And if that was Rekhtah, then what is this?' [See G{111,1}].

The 'only/emphatically' thrust of yihī is then directly echoed in the prophetic start of the second line: is faṣl hī is the time when the singer (and, as SRF observes, perhaps his addressee as well) can expect to be hunted down and captured. The interval between the singing and the capture won't be long. Because the bird's singing makes him conspicuous and easy to locate; and also of course because the superior expertise of his song makes him so desirable a catch that he's worth special attention and effort. As SRF notes, it's hard not to read the verse as reflecting the archetypal melancholy, the romantic doomedness, of (one view of) an artist's destiny.

Note for grammar fans: The non-oblique form koʾī din should just be taken as idiomatic for kisī din .