For Day 31, The one thing God is saying is that everything that sounds "good" may not always be a "God idea". In 1 Chron. 17, David had a good idoea to build a house for the Lord. Sounded good. Even the Prophet Nathan was like ok cool whatever you have in mind do it cause God is with you. ( paraphrasing Vs 2)

However later that night God spoke to the prophet and told him a different thing. he had to recant his declaration to David

What I love about King David was his humility and love for God.  I believe that's one of the reason why he was a man after God's heart. 

Even prophetically the Descendant that would reign for ever was and is Jesus. 

Lesson : Don't speak presumptuously for God  and walk in humility when He course corrects.