The LORD forbid that I should stretch forth my hand against the LORD'S anointed: but, I pray you, take you now the spear that is at his head, and the jar of water, and let us go.
Read Chapter 26
Athanasius the Apostolic
AD 373
For the truth is not preached with swords or with darts, nor by means of soldiers, but by persuasion and counsel. But what persuasion is there where fear of the emperor prevails? Or what counsel is there, when he who withstands them receives at last banishment and death? Even David, although he was a king and had his enemy in his power, did not prevent the soldiers by an exercise of authority when they wished to kill his enemy, but, as the Scripture says, David persuaded his men by arguments, and did not allow them to rise up and put Saul to death. But [the devil], being without arguments of reason, forces all men by his power, that it may be shown to all that their wisdom is not according to God but merely human, and that they who favor the Arian doctrines have indeed no king but Caesar; for by his means it is that these enemies of Christ accomplish whatsoever they wish to do. - "History of the Arians 4.33"
But what great and wonderful and Christian patience is to be found in David from whom Christ descended according to the flesh! David often had the opportunity to kill King Saul, his persecutor, who was eager to destroy him. Yet when Saul was subject to him and in his power, David preferred to save his life and did not retaliate on his enemy but, on the contrary, even avenged him when he was killed. In short, many prophets have been killed, many martyrs have been honored with glorious deaths, and all have attained their heavenly crowns through the merit of patience, for a crown for sorrow and suffering cannot be obtained unless patience in sorrow and suffering precede. - "The Advantage of Patience 10"
After that, the opportunity to kill the enemy presented itself to him twice. Once in the cave Saul fell into David’s hands unawares, and again in the tent when he was relaxed in sleep. David stood over him when he was asleep, and when he could have satisfied all his anger by murdering the one who pursued him, he did not lay a hand on him himself, and he said to the one eager for the kill, “Do not destroy.” The voice which prevents destruction in the case of this man is obviously the voice of God.
For this reason, just as those who produce the more notable inscriptions on stones cut the characters deeply by frequently applying the chisel with blows to the carving of the letters, so the Holy Spirit contrives, by means of continuous repetition, that this great saying may become more distinct and quite clear on the stela of our memory, so that this inscription, having been carved in us distinctly and without confusion, might be known well in the time of misfortunes. For, in my opinion, the...
But this is marvelous not only for the fact that he grants life to the one who is doing everything against his life, but because David, although he had been anointed to the office of king and knew that he would not otherwise partake of that position unless Saul were out of the way, judged it better to suffer ill patiently in his private low estate than to enter upon the kingship by satisfying his anger against the one who had caused him grief. - "On the Inscriptions of the Psalms 2.16.266"