1 Unto the end, a psalm for David. The fool hath said in his heart: There is no God. They are corrupt, and are become abominable in their ways: there is none that doth good, no not one.
Diodorus of Tarsus · AD 390 The psalm's theme, in fact, is clear: it is uttered on the part of David himself when he suffered the effects of the sin with Bathsheba.
Hesychius of Jerusalem · AD 450 The forgetfulness of God [would be] a very serious thing, even temporarily. It would mean death, the loss of immortality.
Thomas Aquinas · AD 1274 In the preceding Psalm the Psalmist set forth the stratagems of his adversaries; here he asks a remedy against them from God. The title: "unto the end, a Psalm of David." This has been explained above. This Psalm is divided into three parts.
2 The Lord hath looked down from heaven upon the children of men, to see if there be any that understand and seek God.
Origen of Alexandria · AD 253 At first this one makes many plans in his soul, but in the end [see v. 5], he rests in the great plan of God for everyone, whose spirit is in the root of Jesse.
Augustine of Hippo · AD 430 "How long shall I place counsel in my soul?" [Psalm 13:2]. There is no need of counsel but in adversity. Therefore "How long shall I place counsel in my soul?" is as if it were said, How long shall I be in adversity?
Thomas Aquinas · AD 1274 Here he confesses his own weakness, and concerning this he does two things. First he sets forth the anxiety of the heart. Second, the resulting sorrow, at "sorrow in my heart by day." As to the first, the Philosopher says in the Rhetoric that fear makes men inclined to take counsel. The same is found in Is.
3 They are all gone aside, they are become unprofitable together: there is none that doth good: no not one. Their throat is an open sepulchre; with their tongues they acted deceitfully: the poison of asps is under their lips. Their mouth is full of cursing and bitterness; their feet are swift to shed blood. Destruction and unhappiness in their ways; and the way of peace they have not known: there is no fear of God before their eyes.
Origen of Alexandria · AD 253 Is God a light to enlighten the eyes of the body or the eyes of the intellect? The prophet says of the latter, "Enlighten my eyes lest I sleep in death." I think it is clear to everyone that we would not say that God performs the work of the sun and assigns to another the task of enlightening the eyes of those who will not sleep in death.
Augustine of Hippo · AD 430 "Look on me, and hear me, O Lord my God" [Psalm 13:3]. "Look on me," refers to what was said, "How long" dost "Thou turn away Your face from me." "Hear," refers to what was said, "How long will You forget me to the end? Lighten my eyes, that I sleep not in death." The eyes of the heart must be understood, that they be not closed by the pleasurable eclipse of sin.
Thomas Aquinas · AD 1274 The second part of this Psalm sets forth the prayer or petition. And first the petition is set forth corresponding to God's seeming indifference. Second, to his own weakness, at "enlighten my eyes," etc. Third, to the prosperity of his enemies, at "lest my enemy say," etc. First he speaks of God's seeming indifference through forgetfulness and turning away.
4 Shall not all they know that work iniquity, who devour my people as they eat bread?
Eusebius of Caesarea · AD 339 As we sin, the adversary becomes haughty and domineering over us, and we are pressed down by our sin; this is really the nature of sin, to cast down and to oppress the spirit.
Augustine of Hippo · AD 430 "Lest at any time mine enemy say, I have prevailed against him" [Psalm 13:4]. The devil's mockery is to be feared. "They that trouble me will exult, if I be moved;" the devil and his angels; who exulted not over that righteous man, Job, when they troubled him; because he was not moved, that is, did not draw back from the steadfastness of his faith. [Job 2:3]
Thomas Aquinas · AD 1274 The petition against the adversary: "lest my enemy say." And he sets forth two things. First, the petition. Second, its reason, at "those who trouble me." "Enlighten me, lest my enemy say," exultantly: "I have prevailed against him." And the Devil exults when he tempts and draws one into sin.
5 They have not called upon the Lord: there have they trembled for fear, where there was no fear.
John Chrysostom · AD 407 Do you see a hope-filled soul? He asked, and before receiving he gives thanks as though having received, sings praise to God and achieves all that had been anticipated.
Theodoret of Cyrus · AD 458 It is clear also from this that he uttered this psalm after the sin: he relies not on his righteousness but on mercy and says it is in this that he trusts.
Thomas Aquinas · AD 1274 Here the hearing of his prayer is signified, and concerning this he does three things. First he sets forth the hope of being heard. Second, the joy over being heard, at "and my heart shall rejoice." Third, he gives thanks, at "I will sing." He says therefore, "in your mercy I have hoped," not in the world. Lam.
6 For the Lord is in the just generation: you have confounded the counsel of the poor man; but the Lord is his hope.
John Chrysostom · AD 407 Hope in God's mercy, have no doubts, and you will gain your request completely; once gained, however, do not prove ungrateful for the favor and unappreciative but make a record of the kindness and offer it as a thanksgiving song to the Lord.
Augustine of Hippo · AD 430 "My heart shall exult in Your salvation;" in Christ, in the Wisdom of God. "I will sing to the Lord who has given me good things;" spiritual good things, not belonging to man's day. "And I will chant to the name of the Lord most high" [Psalm 13:6]; that is, I give thanks with joy, and in most due order employ my body, which is the song of the spiritual soul.
Thomas Aquinas · AD 1274 The second is prayer or the praise of God; hence he adds, "I will sing to the Lord," that is, I will praise Him. Ps. 21: "You who fear the Lord, praise Him." For the praise of God avails greatly for vanquishing the Devil. Mt. 17: "This kind of demon is not cast out except by prayer and fasting." Hab.
7 Who shall give out of Sion the salvation of Israel? when the Lord shall have turned away the captivity of his people, Jacob shall rejoice, and Israel shall be glad.