Proverbs 3:21-23
My son, let them not escape from your sight, but keep sound wisdom and discretion, and they will be life to your soul (your inner self) and a gracious adornment to your neck (your outer self). Then you will walk on your way securely and your foot will not stumble. 

Deuteronomy says that if they keep the law of God, they will prosper. They are to teach the laws of God to the children and talk about them daily with the family.  This was important to keep wisdom and knowledge of the ways of God fresh in their minds. Wisdom comes when we keep the mind focused on the Word and clear of clutter.