So here is another excellent quote from Fred Klooster on the illumination of the Holy Spirit and how it is inextricably tied with heart-understanding. Read it, and then read it again to make certain you didn't omit anything:
The internal testimony of the Holy Spirit is a heart-rooted conviction that Scripture is the authoritative Word of God. Similarly, the continuing process of biblical interpretation in the process of sanctification should aim also at heart-understanding. Interpretation of Scripture involves much more than head-knowledge or the gaining of information, historical or other. That is why illumination is a continuing need.—Klooster, "The Role of the Holy Spirit in the Hermeneutical Process," in Hermeneutics, Inerrancy, and the Bible, ed. by Radmacher and Preus (Zondervan, 1984), 461-62.