Get out the microscope, because we’re going through this poem line-by-line.
Lines 21-22
And so Tom awoke; and we rose in the dark,
And got with our bags and our brushes to work.
In these lines, the speaker finishes narrating Tom's dream, and describes how he (Tom) awoke and the two of them grabbed their chimney-sweeping equipment and went off to work really early in the morning.
But why? Lil' Tom was having such a nice dream. And it was blissfully chimney-free.
One thing to note here, beyond the wonky word order in line 22, is the slant rhyme or near rhyme at the ends of the lines. Dark does not rhyme with work in the strictest sense of the word (but it's pretty close).
All the other rhymes so far have been (for the most part, with the exception of behind and wind) spot-on. So why change it up now?
Maybe Blake wants us to feel a little off-kilter when we get to the final lines of the poem, which pack quite the punch.
Lines 23-24
Though the morning was cold, Tom was happy and warm;
So if all do their duty they need not fear harm.
Here it is, Shmoopers—the big finale.
The speaker tells us that despite the fact that it's totally frigid outside, and these kids are having to get to (hard) work in the wee small hours, Tom's all right with it all.
Wait. Tom was just awakened from an awesome dream, only to have to go to work. How can he be so happy and warm?
Ah, this is where things get interesting.
See, Tom's happy and warm because he believes (thanks to the lesson the angel gives him in that dream) that if you do your duty, no harm will come to you.
In other words, if he keeps chimney sweeping like a good little boy, he'll be taken care of.
Hold your horses. Does that sound right to you? Given everything you know about how awful chimney sweeping is, and that many of these tiny tots were forced into it, is the speaker really saying that no harm will come to them if they keep doing it?
We don't think so.
Shmoop is calling his bluff. We think Blake is being ironic here, to show us that these kids suffer twofold. Not only do they physically suffer, but they also suffer mentally and emotionally, too.
We might think of Tom's belief is a coping mechanism; the only way to get through the day is to believe that they don't have to fear harm. But the sad part is, they totally do.
And remember that slant rhyme we saw in lines 21 and 22? It kind of threw us off balance as we entered the finale of the poem.
Well, what do you know? There's another slant rhyme here. Warm and harm may look alike, but they definitely don't rhyme perfectly. And that has the effect of unsettling us even further. It hints that not everything here is as it seems.