LEV625 [The] trait of cruelty in a man's soul incites him to take revenge on his enemies, as it is written (Mishlei 6:34): "And he will not be merciful in the day of revenge"--that is, where there is revenge, there is not mercy but cruelty, and the Torah has instructed [this verse]: "Do not take revenge and do not bear a grudge." We have been exhorted not even to bear a grudge against our neighbor in our hearts, how much more so not to actively strike him. Even if he falls without our causing him to do so, we are forbidding to rejoice, as it is written (Mishlei 24:17): "When your foe falls, do not rejoice; and when he stumbles, let not your heart be glad." He who takes revenge and bears grudges does not overlook injury and does not forgive his friends who offend him, and this bears in its trail contention and hatred--and you already know how good and pleasant is the trait of peace.