What do ya think it means: Matthew 9:13 says go learn what I will have mercy, not sacrifice (Hosea 6:6) means?

That Christ wasn't there for those who were already righteous and godly and he wasn't impressed with them making grand sacrifices to god. Christ wanted to see these people being merciful to the sick and sinners and showing compassion to others rather than wasting their time making grand overtures to god.