4 He that hath clean hands, and a pure heart; who hath not lifted up his soul unto vanity, nor sworn deceitfully.
5 He shall receive the blessing from the LORD, and righteousness from the God of his salvation.
It’s simple we must be pure before God. Think of how hard it would be to never get mad or sin. We all have dirt on our hands before comeing to Christ. The thing is when this was written Christ had yet to come. So we had to literally sacrifice to be forgiven. Now we have the greatest sacrifice that washes our soul clean. It doesn’t matter how vile you were before, his blood will wash you white as snow. He makes it so when we mess up we can turn to him forgiveness. Now before you go to pray for a need in your life, stop and first pray and ask God to forgive you and be pure before going forward.