Musar su Salmi 35:13

For the cruel person feels no pain at the troubles of his companions, as you see in contrast with David who said: "As for me, when they were sick, my clothing was sackcloth, I afflicted my soul with fasting, and as for my prayer for them — may it return to my own bosom" (Ps. 35:13). And in the Book of Job it is written: "If I have not wept for him that was in trouble and if my soul grieved not for the needy" (Job 30:25). And all this is very far from the cruel man. This trait of cruelty is found only in people whose natures are like the nature of lions that prey and violently rend. When the spirit of wrath takes strong hold of a man then the quality of mercy flees, and Cruelty grows powerful to ruin and destroy as it is written: "Wrath is cruel and anger is overwhelming" (Prov. 27:4). There is no wrath like the anger of Cruelty. In the attributes of the Creator, may He be Blessed, you will find : "In wrath remember Compassion" (Hab. 3:2). But this is far from man's ability — to have mercy in the midst of his anger. And there is this aspect of the quality of Cruelty in the soul of man — to avenge himself on his enemies as it is written: "And he will not spare in the day of vengeance" (Prov. 6:14). The meaning of this verse is that where there is the desire for vengeance there is no compassion, only cruelty. And Scripture says: "You shall not avenge nor bear a grudge" (Lev 19:18). We are warned not to bear a grudge even in our heart — all the more so not to do any deed with the hands to hurt a companion. Even when your enemy has fallen through no fault of yours, you must not rejoice as it is written: "Rejoice not when your enemy falls and when he stumbles let not your heart be glad" (Prov. 24:17). The avenger or the grudge-holder never overlooks a grievance and never forgives his companions who have wronged him, and this attitude drags after it quarrels and hatred, and you already know how good and how pleasant is the quality of peace.

ויגש אברהם . The Midrash Ne'elam of the Zohar on this verse (Sullam edition page 60) quotes Rabbi as saying that it is a מצוה for a person to pray that sinners become penitent so that they will not wind up in purgatory. We know this because it says in Psalms 35,13: ואני בחלותם לבושי שק, "Yet when they were sick, my dress was sackcloth." [David prayed when sinners suffered afflictions. Ed.] Rabbi also says that it is forbidden to pray that the sinners should be wiped out, for if G–d had wiped out Terach while he was still an idol-worshiper, our patriarch Abraham would never have seen the light of day, there would have been no Jewish people, neither would there have been a David. Torah would not have been given to mankind, and all the righteous and pious people would never have existed.

But he who does kindness will receive kindness, and the more he does, the more he will receive. David would exult in possessing this good trait, striving to do kindness even to those who hated him, as written "but when they were sick, my clothing was sackcloth; I afflicted my soul with fastings" (Tehilim 35:13), and "if I have repaid the one who did evil to me" (Tehilim 7:5).