Jesus is referring to the sixth commandment (Exodus 20:13; Deuteronomy 5:17), 1 the unlawful taking of human life. In his teaching, he will make it clear that murder is not only about the shedding of blood but includes the attitudes and desires of the heart. 2 He will challenge the view that wicked thoughts can be tolerated as long as they are not acted upon. 3
21 “You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’