har gaam aabile se hai dil dar tah-e qadam
kyaa biim ahl-e dard ko sa;xtii-e raah kaa
1) at every step, like a blister,
the heart is beneath the footstep
2a) what dread the people of pain/sympathy have, of the harshness
of the road!
2b) what dread do the people of pain/sympathy have, of the harshness
of the road?!
tah : 'adj. (in comp.) Under, beneath, underground'. (Platts p.345)
biim : 'Fear, terror, dread; danger, risk'. (Platts p.211)
dard : 'Pain, ache; affliction; pity, compassion, sympathy; affection'. (Platts p.511)
The one who is a heart-possessor, he is a 'person of pain'; and the person with a blister on his foot too is a 'person of pain'. This commonality of meaning in the words has created pleasure in the verse.... Ghalib says that those who are 'people of the heart', 'people of pain', have no fear of the harshness of the road-- those blister-footed ones consider that the heart is beneath their feet [Zamin's text has varnah har qadam].
== Zamin, p. 64
The road is harsh and full of pain. The feet have become blistered, but because of the blisters the heart is fallen into the blisters themselves. If this would be taken in the dictionary meaning, then it's as if the heart has been bound beneath the blisters. Then what trouble can there be from the blisters? The heart is doing the work of a bandage for the blisters. The people of pain have no fear of the harshness of the road.
For background see S. R. Faruqi's choices. For more on Ghalib's unpublished verses, see the discussion in {4,8x}.
What does it mean for the heart to be 'like a blister'? Perhaps that, like a blister, it is a source of 'pain'. Thus it isn't surprising that the hearts of the 'people of pain' have 'sunk' so low that they are actually under foot, for the 'people of pain' travel a harsh road of suffering, as in (2a). And the 'dread' they feel is not necessarily to their discredit, for the beautifully chosen dard can refer either to one's own 'pain', or to one's 'sympathy, compassion' for the pain of another (see the definition above).
Or perhaps the heart is 'like a blister' in constantly making itself felt beneath the foot. Thus the 'people of pain' are fortified by their hearts, which somehow protectively cushion their feet from the harshness of the road, so that they feel no dread of it at all, as in (2b). The hearts of lovers, after all, are capable in the ghazal world of feats even more extraordinary than this.
Asi:
In a state of blister-footedness, the people of pain are traveling, and in this state because of blisters every step, so to speak, is falling on the heart. Thus there's the fear that they're obliged to trample/crush their hearts. Otherwise [Asi's text has varnah har qadam], what fear of the harshness of the road can the people of pain have? In this, every blister has been assumed to be a heart.
== Asi, p. 67