The word is called a hammer. Jer. 23:29. Every blow of the hammer is to fasten the nails of the building; so the preacher's words are to fasten you the more to Christ; they weaken themselves to strengthen and settle you. This is the grand design of preaching, no only for the enlightening, but for the establishing of souls; not only to guide them in the right way, but to keep them in it.
-- Thomas Watson (from A Body of Divinity, pp. 1-2)
Is not my word like fire, declares the Lord, and like a hammer that breaks the rock in pieces? Jeremiah 23:29 (ESV)
Image credit: "Thomas Watson (Puritan)" by Eugenio.Graziano - Own work. Licensed under Public Domain via Wikimedia Commons