She might well force me to prove my mettle!
At 6 feet 1 inch and 235 pounds, he had proved his mettle.
Ed still has much to do to prove his mettle.
Of course, she had to go out into the world sometime and prove her mettle.
The two best contestants move to the final five while the rest will have to prove their mettle again.
When that force comes into being in December, it will quickly have to prove its mettle.
I will take on any challenger just to prove my mettle.
Maybe this meant that they wouldn't have to move into the field and kill people as frequently to prove their mettle.
Said he'd settle for a share of the inn, and a chance to prove his mettle when the time came.
Or he'll prove his mettle and they will accept him.
Idiome