I’ve heard it. You’ve heard it.
“We go the extra mile.”
“He is a great worker, always going the extra mile.”
“We need someone with initiative; someone willing to go the extra mile.”
I never knew the origin of the phrase until recently. Les Parrot shares the source in his book 3 Seconds: The Power of Thinking Twice.
[Roman Soldiers] often carried heavy packs for great distances. Many of these soldiers, walking through a civilian area, would order a person to carry their pack for them. The practice was so common—and so resented—that a law was passed in the empire that required a young boy given this order to carry the soldier’s backpack for a Roman mile, or about a thousand paces, in either direction from his home. In those days, it was not unusual to see sticks in the ground along village lanes, where boys had marked off the distances they would have to walk if a soldier requested it.