What made Ezra so special?  Why was he unique?  Why was he sent to teach the people?  There are two important things: Ezra set his heart to study the Law of the Lord, AND he put the Law of the Lord into practice.  Both are required for wisdom.  When I worked with teenagers, I often heard them lament about how they just wished they knew what God wanted them to do.  The first part of the problem was that they didn't set their hearts to studying God's Word.  God's moral will is made obvious to us through His Word.  We know what he thinks on moral issue, so we don't need to pray for direction when it comes to those ("hmm… should I murder him or not?" isn't too hard to figure out).  From His Word we find God's character, and we begin to understand His desires for us.  The second part comes when God's Word is then put into practice.  It's not enough to just know the Word; wisdom comes when the Word is lived out.  Wisdom isn't that hard to attain; it just requires determination.  Ezra didn't just set his heart to know the Word; he actually lived it.