Who said "The work of a warrior is never truly finished."?

This quote is attributed to Lady Sif.

The work of a warrior is never truly finished. - Lady Sif

"The work of a warrior is never truly finished."

Lady Sif Work

"I am a warrior of Asgard, and I will not falter in the face of darkness."

"Strength is not measured by the power of one's blade, but by the resolve of one's heart."

"A true friend stands beside you, not behind you."

"We are forged in battle, but refined through compassion."

"Hard work never killed anybody."

"Work with purpose and integrity."

"Hard work pays off in the end."

"A man's gotta do what a man's gotta do."