Verse 9 suggests that the author of the psalm is a young person concerned about how to live a pure life. (Of course, the author could be an older person giving advice to a younger person.)
It is good to have this concern, but merely having the concern is insufficient and pointless. In addition there has to be action, and the activity required is familiarity with the Word of God. The author likens the Bible to protective information. Some people treat the Bible similar to how passengers ignore the information given by airline staff regarding what to do in an emergency. I have sometimes wondered what the passengers would do if there was a situation in which they had to use the life-jackets. It would be very serious for them if through their own choice they had failed to read about or listen to what to do. And in a far higher sense, we need to know what the Bible says.
There is not an issue we can face in life that the Bible does not speak about. Yet the information is not dropped into our minds from the sky. Instead we have to do what the psalmist did in verse 11: ‘I have stored up your word in my heart, that I might not sin against you.’ As Spurgeon says about this practice: ‘He laid it up in the place of love and life, and it filled the chamber with sweetness and light.’ Promises, principles and warnings in the Bible have to be read and thought about before we will know what to do with them.
What kind of person will treat the Bible in this way? We are told what he is like in verse 10: ‘With my whole heart I seek you; let me not wander from your commandments!’ That statement says at least two things: first, the individual is focussed on getting to know God; second, the person is afraid of departing from God through not remaining close to him. Therefore he prays about it, which is what marks a person who takes seriously the requirement to know God’s Word.
In verse 12 the psalmist expresses his gratitude to the Lord for teaching him about the Bible, especially about how to live a holy life. Yet he also knows that he is obligated to pass it on to others: ‘With my lips I declare all the rules of your mouth’ (v. 13). Since we have discovered the best way to live (obedience to God’s commandments), it is our responsibility to tell others about it.
The psalmist tells us what the effect of heart obedience to the Bible is – delight (vv. 14, 16). Are you a happy Christian? If not, the reason most likely is that you are not reading and meditating on the Bible. You cannot expect God’s blessing if you ignore his word and don’t feed your soul on what it says. In order for this to happen there has to be determination (verse 15: ‘I will meditate on your precepts and fix my eyes on your ways’) and recollection (verse 16: ‘I will not forget your word’).