I sit and look out upon all the sorrows of the world, and upon all
oppression and shame;
I hear secret convulsive sobs from young men at anguish with
themselves, remorseful after deeds done;
I see in low life the mother misused by her children, dying,
These two lines are are the kernel of the whole poem. 
 In the following lines, Whitman goes on to describe the specific “sorrows of the world” in his characteristically enumerative fashion.
I Sit and Look Out