Ps 137:1

“"I will confess to you, Lord, with all my heart." The nature of a wound determines the medication to be applied. Just as the body has wounds of various kinds, so also the soul has its passions and its wounds, and we must do penance in proportion to the nature of our sin. If a person makes confession of all his sins, he is acknowledging his sins to the Lord wholeheartedly. If, for example, someone has committed fornication and he confesses only that and is greedy, or quick-tempered, or a slanderer or blasphemer and is full of faults and vices, his confession is not sincere. The person who repents for all the sins and passions of his soul is the person who is able to say, I confess and give thanks to you, O Lord, with all my heart. "For you have heard the words of my mouth." This verse is not found in the Hebrew text. Nonetheless, what it means is, In my confession I have poured out my whole heart, O Lord; I have confessed all my sins and faults, for I have not admitted merely one sin to you, and you have listened to me graciously.”

“The title of this Psalm is brief and simple, and need not detain us; since we know whose resemblance David wore, and since in him we recognise ourselves also, for we too are members of that Body. The whole title is, "To David himself." Let us see then, what is to David himself. The title of the Psalm is wont to tell us what is treated of within it: but in this, since the title informs us not of this, but tells us only to Whom it is chanted, the first verse tells us what is treated of in the whole Psalm, "I will confess to You." This confession then let us hear. But first I remind you, that the term confession in Scripture, when we speak of confession to God, is used in two senses, of sin, and of praise. But confession of sin all know, confession of praise few attend to. So well known is confession of sin, that, wherever in Scripture we hear the words, "I will confess to You, O Lord," or, "we will confess to You," immediately, through habitually understanding in this way, our hands hurry to beating our breast: so entirely are men wont not to understand confession to be of anything, save of sin. But was then our Lord Jesus Christ Himself too a sinner, who says in the Gospel, "I confess to You, Father, Lord of heaven and earth"? He goes on to say what He confesses, that we might understand His confession to be of praise, not of sin, "I confess to You, Father, Lord of heaven and earth, because You have hid these things from the wise and prudent, and hast revealed them unto babes." He praised the Father, he praised God, because He despises not the humble, but the proud. And such confession are we now going to hear, of praise of God, of thanksgiving. "With my whole heart." My whole heart I lay upon the altar of Your praise, an whole burnt-offering of praise I offer to You...."I will confess to You, O Lord, with my whole heart: for You have heard the words of my mouth" [Psalm 138:1]. What mouth, save my heart? For there have we the voice which God hears, which ear of man knows not at all. We have then a mouth within, there do we ask, thence do we ask, and if we have prepared a lodging or an house for God, there do we speak, there are we heard. "For He is not far from every one of us, for in Him we live, and move, and have our being." [Acts 17:27-28] Nought makes you far off from God, save sin only. Cast down the middle wall of sin, and you are with Him whom you ask.”

“It is no secret that angels are frequently present, invisibly, at the side of the elect, in order to defend them from the snares of the cunning enemy and uphold them by the great gift of heavenly desire. The apostle attests to this when he says, "Are they not all ministering spirits sent to serve on account of those who receive an inheritance of salvation?" Nevertheless, we should believe that the angelic spirits are especially present to us when we give ourselves in a special way to divine services, that is, when we enter a church and open our ears to sacred reading, or give our attention to psalm singing, or apply ourselves to prayer or celebrate the solemnity of the mass. Hence the apostle advises women to have a veil over their heads in church on account of the angels. And a prophet says, "I will sing psalms to you in the sight of the angels." We are not permitted to doubt that where the mysteries of the Lord's body and blood are being enacted, a gathering of the citizens from on high is present—those who were keeping such careful watch at the tomb where [Christ's] venerable body had been placed and from which he had departed by rising. Hence we must strive meticulously my brothers, when we come into the church to pay the due service of divine praise or to perform the solemnity of the mass, to be always mindful of the angelic presence and to fulfill our heavenly duty with fear and fitting veneration, following the example of the women devoted to God who were afraid when the angels appeared to them at the tomb, and who, we are told, bowed their faces to the earth.”