The Lost Commandment of Jesus - "Thou Shalt Not Be Angry"

This Jesus though he be the Son of the Just One, all that He preaches is grace. But to me this His grace is torment. Envy is the cause of pleasure to us, for Envy at the beginning mixed for me the first shedding of blood. Why is it guilty in the sight of the Son of Mary Who has come commanding, "Thou shall not be angry against your brother?" He has taken away the sword from between brethren; while in the sword of Cain I had pleasure from the beginning. [Ephrem Nisbene Hymns 39.16]