Although some psalms contain prayers combined sporadically with other diverse material, this psalm is almost entirely a supplication in its composition. Therefore it is appropriately designated as such from the start, since its purpose is entirely focused on zeal for prayer.

We speak fully and clearly when we use words taken from divine Scripture. . . . The righteous person alone cleanses his tongue, lips and the voice itself from using more common words, as one acquainted with that verse: You will give an account of every careless word on the day of judgment.^[1] The ears of God do not hear words offered from lying lips, but they receive any word offered from a cleansed tongue accustomed to meditating on divine words.

Although many times [David had] Saul in his grasp, he refrained from doing away with him and instead rendered good for evil; hence he recalled even the night in which he did this, when by night he saved the sleeping Saul from death and allowed no one to deal him a lethal blow. Now, in a figurative manner he calls his disasters nights on account of the gloom of discouragement, as likewise he refers to the test as burning: you examined me by fire, he says, and no wrong was found in me. In other words, just as you would test gold of some sort, you found me unadulterated, O Lord; so far be it from me to harm the enemy that I even kept my tongue free of abuse against him, and what he continues to do I refrained from mentioning.

Who can with confidence say, I am pure from sins? Christ alone is truly and properly able to say these words. . . . When gold is tested by fire, it remains pure and shining. According to Isaiah, out of all people since the beginning of the age, Christ alone did not sin, nor was there any deceit found in his mouth.^[1]

Even before I make the request, my predicament does not escape you, nor are you ignorant of all the designs in my heart that I experience in the night and ponder by day.

Excuse yourself from unprofitable and empty conversation, and be wary in your heart of complaining against others, for they are your brothers, and maybe the complaint will rebound on yourself. Do not find fault with anyone in your mind, and do not make your tongue impure by accusing your neighbor. For the words the deeds of people have not passed my mouth in the utterance of the lips are trustworthy.

When sins are avoided, the path is hard, and the ascent is always difficult. But when we slip toward vices, the road is easy and downhill. But the Lord Christ appeared before us in this world and demonstrated the laws of meekness and self-control. So he rightly says that through the commands of the Lord he walked the hard ways of people with undefiled feet.

What the Lord has commanded seems hard and harsh, that any who wish to follow him should deny themselves. But nothing can be hard and harsh that is commanded by one who helps us to do what he commands. You see, both these things are true, both what is said to him in the psalm: Because of the words of your lips I have kept to hard ways;^[1] and what he himself said, My yoke is easy, and my burden is light.^[2] The fact is, whatever is hard in the commandments is made easy by charity.

In the paths, that is, in your commandments; for if we are devoted followers on the ways that are truly the right ones, then we will obtain the rewards of our heavenly fatherland.

Never by our sole diligence or zeal or by our most tireless efforts can we reach perfection. Human zeal is not enough to win the sublime rewards of blessedness. The Lord must be there to help us and to guide our hearts toward what is good. Every moment we must join in the prayer of David: Direct my footsteps along your paths so that my feet do not move astray and He has settled my feet on a rock and guided my footsteps^[1]—all this so that the invisible guide of the human spirit may direct back toward love of virtue our free will, which in its ignorance of the good and its obsession with passion is carried headlong into sin.

Even if now [the way] is full of pain and without joy, later it will bear the fruit of righteousness for those who have been trained in it.

Human weakness is not strong enough to reach the Father on its own. For when he hears, he graciously shows his indulgence, and he bestows his mercy in advance so that he is able to accept the prayers of those who implore him.

It becomes Christians to pray for peace and quiet but not to abandon steadfast faith and truth even at the peril of death. For the Lord is our Leader, who will save them that put their hope in him.

He teaches us that even if we are virtuous, we should trust not in ourselves but in God, and that we should pray to him that like the pupil of the eye he protect the mind—our soul’s eye—from evil of the opposing powers.

His prayer is to enjoy such protection as does the apple of the eye, which has eyelids as a kind of rampart and eyelashes for a palisade; it also has eyebrows as mounds, conducting the stream of sweat to the temples and warding off from the faculty of sight any harm from that source.

The Father’s protection is compared to wings. Mercy and love are, so to speak, the wings of the Father with which he asks to be protected. This comparison is drawn from the example of birds who guard their own dear offspring by spreading out their wings.

The written words say that God has wings. . . . But we will not on that account say that God’s spiritual and indestructible essence is winged. . . . What, then, are we to understand by the wings? The help, security, shelter, defense and unconquerable aid that God gives us.

This should be the careful consideration of wise people, that since the days of this life are short and the time uncertain, death should never be unexpected for those who are to die. Those who know that they are mortal should not come to an unprepared end. Therefore this, which has been proclaimed by the voice of the prophet, should be taken up in the hearts of those praying, so that it may be said, not with the lips only but also with the heart. . . . For we are always in need of divine help. This is the unconquerable courage of human devotion, that we always have a protector without whom we are not able to be brave.

The demons surround our mind and try to entangle it like a wild beast, . . . and the richest baits are sinners who themselves have been allured by desires.

Through impure thoughts our adversary like a lion overcomes our mind.

That sword will be the word of God living and more active than any double edged sword,^[1] here in the place of a straight sword, which is entrusted to my spirit for driving out the enemies.

The soul of each of the righteous—clearly of those who pull sinners from impiety to piety—is as a sharpened sword against the spirits of evil. This sword, O our Lord, which you sharpened against your enemies, save from the enemies of your hand.

Since I do not know how to ask for manifest punishment of them, whereas you are aware, having as you do hidden treasuries of wisdom, inflict on them the punishments you best know.

Here the psalmist is not criticizing the children’s food, as some would think (for those things that enter the mouth do not make a person unclean^[1]), but he regards those to whom God has given many offspring unwise when they leave behind them not excellence but their evils as an inheritance.

Why talk about those treasures of wisdom and knowledge, about those divine riches, if not because they are what suffices us? And why talk about that multitudinous sweetness, if not because it is what satisfies us? . . . In one of the psalms somebody, one of us, or in us, or for us says to him, I will be satisfied when your glory is revealed. . . . He will convert us and show us his face, and we shall be saved;^[1] we shall be satisfied, and it will suffice us.

When shall we be satisfied? . . . When your glory is revealed. Now though, the glory of our God, the glory of our Christ, is concealed; and with it is concealed ours also. But when Christ appears, your life, then you too will appear with him in glory.^[1]

In the [present] life we need the light of the sacred Scriptures and the refreshment of the heavenly sacraments, but in the future we shall have no need of such aids. According to the word of the psalmist, whoever appears there will be fully satisfied with justice when the glory of the Lord is made manifest.

What this future glory will be like, however, how richly it will flourish, with what splendor it will blaze out, while we can sing its praises, we cannot possibly explain. Why not? Because we read, Eye has not seen, nor ear heard, nor has it come up into the human heart, what things God has prepared for those who love him.^[1] So if that is what has to be said about the eternal good things of heaven, . . . what must God himself be, who has prepared such great and wonderful things? What, I repeat, must almighty God be like? What but unfathomable, inexpressible, incomprehensible, surpassing all things, beyond all things, apart from all things? He excels, after all, every one of his creatures; he goes far beyond everything he has made; he surpasses the whole universe. I mean, if you are looking for greatness, he is greater; if for beauty, he is more beautiful still; if for delightfulness, he is still more delightful; if for splendor, he is more brilliant; if for justice, he is more just; if for strength, he is stronger; if for fatherly care, he is kinder. Reason, after all, in no way allows us to equate the thing made with its maker or the work with its craftsman.