The best law for Bible study is the law of perseverance. The Psalmist says, "I have _stuck_ unto thy testimonies." Application to the Word will tend to its growth within and its multiplication without. Some people are like express-trains, they skims along so quickly that they see nothing.
I met a lawyer in Chicago who told me he had spent two years in studying up one subject; he was trying to smash a will. He made it his business to read everything on wills he could get. Then he went into court and he talked two days about that will; he was full of it; he could not talk about anything else but wills. That is the way with the Bible--study it and study it, one subject at a time, until you become filled with it.
Read the Bible itself--do not spend all your time on commentaries and helps. If a man spent all his time reading up the chemical constituents of bread and milk, he would soon starve.