It's just as well that the children are crying, because they're too tired to run. They have never seen the sun, or the light of God, which is even brighter than the sun. They're familiar with grief, but don't have the wisdom of age, which normally accompanies grief. They're familiar with despair, but not calm resignation. They're slaves and martyrs, but not in the dignified, submissive sense of Christian mythology. They have all the tiredness of old age but don't have any good memories to sustain them. They've been deprived of love from both people and God, so they should be permitted to cry.
The children look up so sadly that it's terrible to witness. They believe that we already see them as angels, turned towards God. The children ask how long people will willingly stand on their hearts in the name of national progress, crushing their heartbeats with an armor-clad foot as they walk to their throne. The children's blood splashes, even though the tyrannical adults walk forward on a carpet of purple, the color of royalty. But, the children warn, the cries of a child are a curse, much worse than anything a strong man's anger can bring about.
Two major changes take place in these ending stanzas. As discussed earlier, for most of the poem, the speaker acts as a kind of interpreter. The children only get to speak via the speaker, who quotes or paraphrases their lament. Here, at the poem's end, the children take over the narration. True, the speaker is still quoting them, but they speak for a long amount of time with no interruption—eight consecutive lines. This in itself isn't unprecedented within the poem, but the speaker never reenters to contextualize those eight lines: they end the poem, meaning the children get the final word. Most importantly, the children directly address and accuse the outside world and the reader. The speaker, once the mediator between the children and the reader, fades to allow a direct conversation between the two. For a brief but memorable few lines, the children openly and directly condemn the reader.
Even more dramatically, the poem's register shifts at the end, using the language of epic and legend. Most of the poem has taken place in a firmly Victorian rhetorical universe. Its language can be fanciful, but its images are of industrial machinery, meadows, mines, and nineteenth-century Christianity. This changes radically in the final stanza, when, via metaphor, Browning creates an almost medieval scene replete with armor, thrones, and blood. By situating the children's conflict in a world of epic battles between good and evil, Browning creates clear moral stakes and removes any of the bureaucratic distance separating victim from tyrant within a modern capitalist society. It also establishes the children as martyrs, slotting them into a more dramatic role than that of mere downtrodden victims, and giving their suffering a drama and dignity that it otherwise lacks.