"Now you Pharisees cleanse the outside of the cup and of the dish, but inside you are full of greed and wickedness” (v39). Jesus had harsh words for people who were very concerned about being seen as “righteous” but were hiding sinful attitudes and heart motivations. They tithed carefully and followed the Law but neglected “justice and the love of God” (v42). Jesus called for them to “give as alms those things that are within” (v41), at the heart level, and then the rest of morality would follow.
“Did not he who made the outside make the inside also?” (v40). God sees our hearts and calls for loving obedience to Him when no one else is watching.