Who said "Fire cannot burn what has already frozen."?

This quote is attributed to The Night King.

Fire cannot burn what has already frozen. - The Night King

"Fire cannot burn what has already frozen."

The Night King Strength

"The living are not my concern."

"Death is the enemy. And we are joining the fight against it."

"Winter came for House Umber."

"I am the night."

"Strength comes from within."

"A woman should be proud of who she is."

"A strong woman can overcome anything."

"The only thing I'm good at is killing."