Gregory the Great — on 1Sam 13:14 (Commentary on 1 Kings, Book 5, Chapter 3)

“20. Behold how great were the things he lost, who, as he supposed, despised nothing. Behold, for seven days he waited for the prophet; but when he ceased to await him at the end of the day, he lost the glory of so great a dignity. Whence it is also said through the prophet: 'Woe to those who have lost patience' (Sirach 2:16). Indeed, those lose patience who do not bring to completion the good things they have begun. To whom assuredly woe is pronounced: because they not only lose the reward of the labor they began, but are also struck with the punishment of their apostasy. Moreover, the punishment of the proud and disobedient king is declared when it is said: 'If you had not done this, the Lord would already have prepared your kingdom over Israel from now and forever; but it shall not stand.' From now and forever the kingdom is prepared for the elect: because those who rightly order temporal things prepare for themselves the height of eternal glory. Indeed, the kingdom of the elect is prepared now, when through divine grace their ministries are rightly administered. Which advances from now and forever: because from the lofty action of this present time, they merit that still loftier glory of eternity in heaven. And so finally it is said to the reprobate king: 'Your kingdom shall by no means stand any longer.' As if to say: Since he falls short of temporal righteousness, he does not attain to the height of eternity. Or for this reason it is said literally that it shall not stand: because it fell with him, and after him it did not remain in his sons. But, so that he may be struck with the punishment of envy, he is compelled to hear not only his own rejection, but also the election of another. For the prophet, continuing, says: (Verse 14) 'The Lord has sought for Himself a man after His own heart, and has commanded him to be leader over His people Israel.' 21. By all these words the proud man is struck down: "He sought," it says, "a man after His own heart." As if to say: He sought him for that reason, because you were unwilling to be according to His heart. As if to say: He appointed such a man as leader of His people, one who would carry out the command of divine counsel with the virtue of devotion. For since we are accustomed to deliberate in our heart about the things we wish to do, when by the usage of our speech the heart of God is spoken of in sacred Scripture, His inmost will is signified by it, which is then recognized by us outwardly when the commands of disobedience are revealed. But we are close to it when we both recognize it through understanding and guard it through love. Rightly, therefore, the prophet Samuel says of the Lord: "He sought for Himself a man after His own heart, and He commanded him to be a leader over His people." Because he profitably commands others who already knows how to obey God perfectly; who commands only that which proceeds from the counsel of the inmost truth. 22. But what does it mean that it is said as if of the past: "The Lord sought for Himself a man, and commanded him to be a leader," when he had not yet been sought, nor had it been enjoined upon him to preside over His people? For after Saul struck Amalek, the Lord said to that same prophet: "Fill your horn with oil, and come, I will send you to Jesse the Bethlehemite" (1 Sam. 16:1). But this question is easily resolved if the foreknowledge and predestination of Almighty God are considered. For to Him, to predestine is to do, and those things which have been preordained by Him to be done are already done in His sight. Whence it is also written of Him: "He has done the things that are to come" (Isa. 45:11, according to the LXX). But God is said to have sought a man so that a pattern for choosing bishops might be set before men. For we are accustomed to seek things that we either do not recognize when present or do not see when absent. But God, from whom nothing is absent, nothing hidden, is not said to have sought a man as one absent or concealed; rather, He is said to have sought so that it might be taught that everyone who is chosen for the summit of the holy Church must be examined by men. But he must be sought according to God's heart, so that he may not only understand the divine will but also demonstrate it through good works. Because likewise chosen men do not come to the honor of primacy out of ambition but are led to it under compulsion, it is well said: "And He commanded him to be a leader." As if to say: He did not enter the honor of prelacy through ambition but ascended under compulsion. "Man" can also be understood as referring to fortitude, and "according to God's heart" as referring to interior charity. Therefore, when necessity demands, let a man be sought for the care of the holy Church who is strong in his manner of life; let him be sought according to God's heart, so that through the effect of great love he may be, as it were, united to the divine will; let him be commanded to be a leader, so that he may not aspire to ascend the rank of high office out of desire but may fear it out of humility — and thus, humble, may fear for himself, so that he may more devoutly recognize that he must submit to the command of God. But because with these words the prophet had rebuked the life of the fallen king, there follows...”