So, Psalm 5:
Hearken to my speech, O Lord,Usually, though, the repetition either intensifies the previous line, or offers the next little step. So in line 12 we rejoice, then we get more specific -- we sing. And then we get a more intensive version -- we exult!
attend to my utterance. 
You destroy the pronouncer of lies,
a man of blood and deceit the Lord loathes. 
Let all who shelter in You rejoice,
let them sing gladly forever -- protect them!
and those who love Your name exult in You. 
Or in line 7, it looks a bit backwards -- God destroys, then he loathes? But what changes is the group; it's not just the liars, but the violent that are in trouble.
This all fits a little better when you've got the whole poem in front of you. But you have to go slow. As you can tell, it's really, really subtle at times.
That's how I'm taking the next couple lines of the Our Father. What has come before -- the calling of God Father and the desire that all would praise him -- implies that we're talking about the kingdom. But it's only in this line that that kingdom sensibility that lies behind everything Jesus hopes for and wants us to seek becomes clear and evident. If you had to summarize what the Our Father is about, this is it: thy kingdom come.
And beyond specifying the earlier lines, this line adds a new texture from the previous or the next -- that of an activity, an event. We are anticipating, asking for something to happen, something to finally and fully come into being, here, in our world. We're in the story of salvation, and we're praying for the happy ending that got promised back in chapter one. Or at least, a good ending for a chapter or volume. It's that Pauline notion of all creation groaning as something is being born. That's where this line puts us.