An attempt

I'll pick a line from a book and weave it into something. The only problem is to make the line random or at least random-ish. I'll open the book (Andrew Marvell, Complete Poems) and point.
We'll see...
(Dramatic, isn't it? This is real-time stuff.)
... "And the green grass, and their known mangers hate,"
Pretty good so far, especially because I'm not looking at the context, as much as I'd like to because it's not making too much sense.
Here goes:

Two sheep, let's call them Thelma and Louise,
grow increasingly difficult to please.
They longingly gaze past the garden gate,
And the green grass, and their known mangers hate.
But soon, for the first time since they were born,
they wander out, bravely to a new morn
and get shorn.