In a nutshell, Uriel is a fictional planet in Madeleine L'Engle's sci-fi/fantasy book A Wrinkle in Time… 'the third planet of the star Malak in the spiral nebula Messier 101,' to quote the book exactly. It is a beautiful and peaceful planet, inhabited by beautiful and peaceful creatures.
On the way to rescue Dr. Murry, Meg, Charles Wallace, and Calvin make a pit stop on Uriel. The purpose for this pit stop, according to Mrs. Whatsit, is 'more or less to catch our breaths. And to give you (the children) a chance to know what you're up against.'
To fully understand this planet and its role in the story, a little background knowledge is important.
It is thanks to his jealousy that the Frog becomes the sole singer at the end of the poem.
He envied the Nightingale's talent and therefore tricked the Nightingale into practicing so much it died. After the Nightingale's death, the Frog became the only (and therefore best) singer. The Frog's success was only possible due to his jealousy. If he had not been jealous of the Nightingale, the Frog would not have become the singer he became.
c or the 3rd option however u would like to put it
The wilderness rose up to it,
<span>And sprawled around, no longer wild</span>
