"Create a pure heart for me, o G-d, and a steadfast spirit renew within me." (Psalms 51:12)

  This is a very moving verse that many great people would repeat over and over again. It is both a prayer and an affirmation. When you repeat it over and over again, the message of this verse becomes integrated and internalized. You are expressing your fervent desire to have a pure heart. You are asking for a renewal of your spirit.