Who said "Gratitude is what slaves feel toward their masters."?

This quote is attributed to Sauron.

Gratitude is what slaves feel toward their masters. - Sauron

"Gratitude is what slaves feel toward their masters."

Sauron Gratitude

"One does not simply walk into Mordor without purpose and absolute will."

"The Ring is mine. All that exists serves the master of the Ring."

"I am eternal. I am inevitable. I am the darkness that devours all light."

"Those who resist my rule shall know despair beyond measure."

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"