I'm not sure how mesmerized you are listening to the beautiful lyrics in Lootera, but I'm quite so, and not without reason. Especially after I saw the movie, the words seemed to make even more sense. Completely loved the words of Amitabh Bhattacharya.
Anyway, there were two lines in the song Shikaayatein Mitaane Lagi, that I was not sure of whether people would understand or not. At least not the way I understood them. The lines were:
naa udne ki iss dafaa thaani,
parindon ne bhi wafaa jaani..
That is,
They decided not to fly this time,
Even the birds understood (the need, or say importance of) faithfulness this time..
Leaving aside the context of the lines in the movie, how do you interpret them individually in the song. I don't know how others interpreted it, but to me this seemed to come straight from a poem by Shri Maithili Sharan Gupta that I read as a child.
There, when a fire breaks out in a tree, the birds in the tree are asked:
आग लगी इस वृक्ष में, जलते इसके पात,
तुम क्यों जलते पक्षियों, जब पंख तुम्हारे पास?
i.e.,
There is a fire in this tree, it's leaves are burning,
Why do you burn O birds, when you have wings with you?
And the birds reply:
फल खाये इस वृक्ष के, गंदे कीने पात,
यही हमारा धर्म है, हम जलें इसी के साथ.
i.e.,
We ate the fruits of this tree, and dirtied its leaves with our excreta,
Now this is our duty, that we burn with it..
So this was the feeling of patriotism that I believe has been the source of inspiration for Amitabh's words in the song, though, the sense of duty and responsibility here doesn't go exactly as patriotism as per the movie. For confirmation though, he's not available here. Amitabh ji, if you're reading this post somewhere, a comment would be helpful to us.