Deuteronomy 21 God's Laws are meant to  preserve life and to remove guilt.  He desires justice, as in the case of the unsolved murder in verses 1-9;  yet He doesn't reveal the murderer;  instead He calls upon the people to all seek forgiveness, removing the guilt from the community.  

He desires purity in the home, making provision for  circumstances that He really doesn't want to happen - a foreign wife that is let go; the son of an unloved wife that should be treated fairly;  and a rebellious son who is so evil that he is to be stoned to death.  ( verses 10-21)

He also reveals this, " ... he who is hanged is accursed of God..."  talking about someone who is hanged on a tree.  The apostle Paul tells us in Galatians 3, " Christ redeemed us from the curse of the Law, having become a curse for us - for it is written, 'Cursed is everyone who hangs on a tree' - in order that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promise of the Spirit through faith." verses 13-14.

Father,  You are our God, Mighty in all Your ways and so wise and just and kind.  You took Your own Son and allowed Him to take the curse that we deserve and to redeem us.  Hallelujah!  We are set free from every sin and curse in Christ Jesus.  Let us cling to Him and follow Him and worship Him.  May our hearts find our home in You, Jesus.  Draw us closer that we might know and love You more and more.  For it is in Your Name that we come to the foot of the throne of Grace.  Amen.