| Quote #1
Selah. Freedom. (2.20)
"Selah" is a Hebrew word. As Mr. Small tells Thomas, it means "raise the voice" (2.10). It's the name slaves gave to Dies Drear because he helped them raise their voices to find freedom.
| Quote #2
And they returned to bondage hoping to free masses of slaves. (2.7)
Thomas is surprised by this piece of information – that slaves would voluntarily go back into slavery to help save others. It makes sense, though, doesn't it? Slavery divides families, friends, and loved ones from each other. It's natural that those who got away and found help would want to go back and help others, no matter the risk.
| Quote #3
Thomas felt frantically along the wall. The wall was wood. […] Thomas pounded on it, hurting himself more, causing his head to spin. He kept on, because he knew he was about to be taken from behind by something ghostly and cold. (4.5)
In "Genre" we say this is Gothic literature. One of the biggest guys in Gothic fiction is Edgar Allan Poe. This moment seems right out of Poe. He's known for putting his characters in tight spaces. But, unlike many trapped Poe characters, Thomas finds his way out to freedom.