1 Samuel 24
Augustine of Hippo · Comentário Patrístico (catena)
1 Samuel 24:5
In the same way, Saul's kingdom foreshadowed one that should last forever, though he personally was reprobate and rejected. The very oil with which he was anointed (the chrism by token of which he was called a "Christ") must be understood symbolically as pointing to a profound mystery. David himself so religiously respected this anointed state that he was conscience-stricken when, in a dark cave where Saul had entered to ease himself, David came up, unseen, from behind and cut off a tiny piece of Saul's robe. David did this merely to have evidence later how he had spared Saul when he could have killed him, thus hoping to disabuse Saul of the idea which drove him implacably to pursue David as his foe. Nevertheless, David quaked with fear that perhaps merely by so touching Saul's garments he was guilty of sacrilege.… Such deep religious reverence was paid to this foreshadowing figure, not for what it was in itself but precisely because of the reality it typified. - "City of God 17.6"
1 Samuel 24:6
As a Christian judge, you must play the part of a loving father, you must show anger for wrongdoing but remember to make allowance for human weakness; do not indulge your inclination to seek vengeance for the vile acts of sinners, but direct your effort to the cure of the sinners' wounds.… There is also that well-known example of forbearance on the part of holy David, when his enemy was delivered into his hands and he spared him, an example which shines with greater luster from the fact that he had power to act otherwise. Do not, then, let your power of punishment make you harsh, when the necessity of inquiry did not shake your spirit of mildness. — LETTER 133