King David asked God to create in him a clean (pure) heart Ps 51:10. This prayer to God was based on David’s knowledge that God desires truth in the inner being, that he would know wisdom in his inmost heart, and that would require an inner purification by God 51:6-7. Upon purification David knew that his salvation would be restored with a willing spirit, and that he would then be able to teach transgressors God’s ways, and sinners would be converted and return to God 51:12-13.
We see the purification of the heart as foundational to restore the soul back to God. How did David do this and what must we do to be purified and restored to God? We find by reading all of the Psalms that prayer and meditation is the pathway back to God. The words meditate and meditation are used a total of 20 times in the Scriptures; and of that 20, 15 are used in the book of Psalms. Could that be why the Bible says that David was a man after God’s own heart? Ac 13:22. The word prayer is used many times in Psalms also, but more in a way of petitioning God for something, as opposed to transformation of heart through union with God, and his work in us, as meditation does in silence. “Be still and know God.” Ps 46:10.
Meditation is more about letting go and letting God, rather than asking for specific needs. Yet in the letting go of everything except God, all of our real needs are met, and our heart becomes pure solely by the grace of God working in us; and thereby we know God, which is eternal life Jn 17:3.
In Joshua 1:8 we read: “this book of the law shall not depart out of your mouth, but you shall meditate on it day and night, that you may observe and do according to all that is written in it. For then you she don’t make your way prosperous, and then you shall deal wisely and have good success.” It is important that we understand this book of the law not in terms of the letter but in terms of the Spirit; for the letter is of the mind but the Spirit is of the heart as Paul explains in: 2 Co 3.