Who said "Your weapons cannot harm what cannot be harmed."?

This quote is attributed to Smaug.

Your weapons cannot harm what cannot be harmed. - Smaug

"Your weapons cannot harm what cannot be harmed."

Smaug Strength

"I am fire. I am death."

"You have no idea what you're dealing with."

"I am armored above and below with iron scales and hard gems."

"My armor is like tenfold shields, my teeth are swords, my claws spears."

"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."