Who said "Mercy's a luxury we can't afford."?

This quote is attributed to Daryl Dixon.

Mercy's a luxury we can't afford. - Daryl Dixon

"Mercy's a luxury we can't afford."

Daryl Dixon

"I ain't much for words, but I know how to survive."

"You gotta do what you gotta do to keep the people you care about alive."

"Ain't nothing gonna change if we don't change it."

"Fear is natural, but it can't control you."