"I define expository preaching as that mode of Christian preaching which takes as it's central purpose the presentation and application of the text of the Bible. All other issues and concerns are subordinated to the central task of presenting the biblical text. As the Word of God, the text of Scripture has the right to establish both the substance and the structure of the sermon. Genuine exposition takes place when the preacher sets forth the meaning and message of the biblical text and makes clear how the Word of God establishes the identity and worldview of the church as the people of God".
Al Mohler - "Preaching the Cross" - Crossway Books, Illinois (2oo7) - (p66).