Mark 7:6-13

Jesus reacts angrily to the Pharisees. The Pharisees accuse the disciples of ritual uncleanness. Jesus objects to their carping about superficial cleanliness when they are guilty of much larger errors.
Steve Motyer says "The problem with interpreting life through rules is that, sooner or later, mercy is forgotten." He also adds "Rules give comfort to the insecure soul." All of us have insecurities in that realm.
I think I am walking with God. I try to use rules and not be ruled by them. But I am sure, in my insecurity, legalism slips into my life.
Certainly legalism get in the way of God's mercy in my life. But I try to seek understanding and to read admonitions in the Bible to break free.
Sadly when was young my religious zeal kept me from spending time with my parents. I did not need to give them money but I could have given them time. I know my mother was upset with me at times. I cannot think of examples so this may be more the devil's accusation than God's conviction. I did not withhold money as Jesus accuses the Pharisees of doing but I did withhold time from my parents in the name of God.
Later I would join dad's company. I did that at least partially out of a feeling of obligation to my parents. And that obedience to God's call to honor my father worked out very well for me. God has blessed that immensely.
In Mark 7:9-13 Jesus likely has a specific example in mind. As is often the case we do not know all of the story. But the Pharisees, or at least some of them, probably did. Jesus is upset with how they have used God's name to do evil. God wants us to be kind to one another. We do not have to wait for permission to act with mercy.
God is also upset when we use his name to do evil, to withhold mercy. We need to be careful. This is legalism at its worst.