Where did the term elbow grease come from?

The term "elbow grease" is believed to have originated in the 17th century, referring to the physical effort and hard work required to clean or polish something. The phrase suggests that one must apply their own strength and effort, particularly using their elbows, to achieve a desired outcome. It emphasizes the idea that some tasks require more than just superficial effort; they necessitate genuine labor and diligence. The term has since become a colloquial expression for putting in hard work to accomplish a task.