Solomon explained preaching with two images, “The words of the wise are like goads, and the words of scholars are like well-driven nails, given by one Shepherd” (Ecclesiastes 12:11).

A goad is a long pointed stick used to prod livestock. Solomon is saying that good preaching ought to move people forward. It exhorts and urges positive movement.

But Solomon also said that good preaching is like a nail. It “nails down” certain truths, keeps them from slipping away. It locks down bible-based beliefs.

Good preaching then is about both duty and doctrine. It is about behavior and belief. The one takes a goad, the other a nail.