Mark 7:14-15, 20 NIV [14] Again Jesus called the crowd to him and said, “Listen to me, everyone, and understand this. [15] Nothing outside a person can defile them by going into them. Rather, it is what comes out of a person that defiles them.” [20] He went on: “What comes out of a person is what defiles them. https://bible.com/bible/111/mrk.7.14-20.NIV Hence...: Proverbs 4:23 NIV [23] Above all else, guard your heart, for everything you do flows from it. https://bible.com/bible/111/pro.4.23.NIV