Central to Luther’s doctrine of Scripture was the claim that Scripture was clear; from this doctrine of the clarity (or perspicuity) of Scripture came Luther’s method of interpretation (or hermeneutic). Because the clarity of Scripture is a property of the text itself on account of God’s authorship, Luther’s primary hermeneutical approach is prayerful mediation upon each text in light of the whole Bible: if Scripture is clear, then it provides its own tools for interpretation, thus one must look to the whole for light on its parts.
The study of grammar and history and recourse to others’ interpretations are ways to remove the external obstructions of ignorance and error and to form a better grasp of the whole. These are necessary steps yet not because of a deficiency in Scripture: external aids are necessary because of deficiencies in the interpreters of Scripture. Therefore, for Luther, interpreting the Bible involves, first, prayerful study of individual texts in light of the entire Bible and, second, careful study of materials relating to the Bible (history and grammar) and other interpreters in order to strip away ignorance or error in oneself that would prevent proper interpretation.