In A Christmas Carol, Jacob Marley says, “I wear the chain I forged in life”. This is a metaphor for the negative consequences of his actions, which weigh him down as a ghost. Marley made the chain link by link and yard by yard, and he wore it of his own free will.

It’s basically saying Karma is real. It’s meant for a simpler time than today as this story is from Charles Dickens in 1843.