Laws on our Hearts: Who is Israel and Judah in Jeremiah 31, and what laws are being written on the heart ? [Jeremiah 31:31, Jeremiah 23:3-33, Joel 2:32, Romans 10:13]. Establishing the Law: What does it mean when scripture says we "establish the law"? [Romans 3:31-4:3, Genesis 15:6, Galatians 5:4].