Who said "Gratitude is a currency I do not trade in."?

This quote is attributed to Loki's Tesseract.

Gratitude is a currency I do not trade in. - Loki's Tesseract

"Gratitude is a currency I do not trade in."

Loki's Tesseract Gratitude

"I am burdened with glorious purpose."

"Kneel before your king."

"Freedom is life's great illusion."

"I will never be your slave again."

"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"