Meaning
A stone or rock, the hard mineral matter of the earth.
How Iqbal uses it
Sang is the stone in its hardness, the obstacle on the path and the substance that can be struck for fire. Iqbal can use it for the resistant world against which the self proves its strength, the rock that yields a spark when it is struck.
See it in the verse
Sang in Iqbal’s couplets
Jahan-e-taza ki afkar-e-taza se hai numood
Ki sang-o-khisht se hote nahin jahan paida
Ki sang-o-khisht se hote nahin jahan paida
A new world comes into being from new thoughts — for worlds are not built out of stone and brick.
Action · Aspiration · Awakening
Wahi jahan hai tera jis ko tu kare paida
Ye sang-o-khisht nahin jo teri nigah mein hai
Ye sang-o-khisht nahin jo teri nigah mein hai
Yours alone is the world you yourself create; not this one of stone and brick that lies before your eyes.
Selfhood · Action · Aspiration