I have stored up your word in my heart,
that I might not sin against you.
The Word of God is my provision for life and my protection against sin. Knowing God's truth by reading His Word and committing it to my memory provides the best hope for me to make holy decisions in my life. I must be serious about daily exposure to God's Word and the intake of biblical truth and wisdom. It is my source of life as much as food and drink sustain my body.
I like the way the ESV translates this verse, because we store up things for two reasons: value and need. Treasuries exist to save money and resources to drive economies. Silos hold grain for future food. Banks keep money for when it is needed. In the same way I must "store up" God's Word because it is a precious commodity that will never spoil. And in the vault of my heart the Word of God can be ready to comfort and compel me in obedience. It can be the resource of strength when sin comes calling. It can be the armory from which I draw out the Sword of the Spirit to fight against my temptation. But I must treasure it. I must take action to "store it up" through things like journaling, extended reading, and serious meditation upon it through scripture memory.
I thank You for Your Word. And I thank You that more than four decades ago You saw fit to save me, and though I was yet a young boy, You gave me parents who saw that I filled my life with scripture, who took me to church, who encouraged me to participate in scripture memory while my then young mind could soak a lot of it in. I have so much truth in my heart that I've drawn on for a lifetime! Thank You Lord for the treasure and sustaining goodness of Your Word!