Well-Driven Nails: The Power of Finding Your Own Voice,by Byron Yawn:

“The notable expositors of our day share some common traits: efficient mental discipline and a determined capacity for reflection. As Solomon put it, they “ponder.” They think really well and deeply. Is it not the finely-sliced nuance which creates the enviable dynamic in their presentation? They have the capacity to focus their minds on a singular topic or truth for the length of time necessary to penetrate the obvious and unearth the profound. When they do deliver their sermons they come across as ‘well-driven nails’.”