The narrator introduces the boy chimney sweep as no more than a 'little black thing'. The child is so young that he cannot even pronounce the traditional cry of 'sweep, sweep' which the chimney sweeps of Blake's time called out to advertise their presence as they walked through the streets. When the narrator asks him where his parents are, he simply replies that they have 'both gone up to the church to pray'. He then tells how they sold him to be a chimney sweep but still refuse to accept that they have done him any wrong. In the final two lines he attacks the church and the king for pretending that all is right with the world and for closing their eyes to 'our misery'.

In both of the first two verses Blake employs basic colour imagery to contrast the 'little black thing' with the white of the snow, which represents the purity of the childhood that the sweep has had taken away from him. The sweep's clothes are 'clothes of death' not just because the soot has turned them black, the colour of mourning, but also because the soot will soon kill the child. The greatest shock of the poem comes in the second verse, where the boy says it was 'Because I was happy' that his parents condemned him to this early death. Blake has deliberately given us a sentence which doesn't make sense in order to show us how totally wrong it is to violate the purity of the child. The rhythm of the last verse becomes quicker and lighter as the sweep describes how his parents 'praise God' that everything is fine, but slows right down as the biting last line exposes the hypocrisy at the heart of state religion. The law passed by Parliament in 1788 to protect child sweeps had failed to make any difference by the time Blake published Songs of Experience in 1794. The poet's anger at society's indifference blazes out as never before.

Compare this poem with its 'contrary', 'The Chimney Sweeper' in Songs of Innocence.