Ps 102:1

“In like manner, "these fatty parts of the ram that are around the kidneys and these that cover the interior parts" are commanded to be placed on the altar. So you who hear these things should know you ought to offer on the fire of the altar everything that is more sinful within you and hides your "inner being" so that all your "inner being" may be cleansed and you also may say, as David said, "Bless the Lord, my soul, and all that is within me, bless his holy name." For unless that sinfulness that touches your "inner being" should be removed, your inner being cannot lay hold of the subtle and spiritual sense and cannot receive the understanding of wisdom; therefore, it cannot praise the Lord.”

“[Daniel 10:16] "O my lord, at the sight of thee my joints are loosed..." Theodotion interprets it this way, in accordance with what we read in the One Hundred and Second Psalm: "Bless the Lord, O my soul, and all that is within me, bless His holy name." (Psalm 103:1) For our inward nature must direct its gaze without, before we deserve to behold a vision of God; and when we actually have beheld a vision of God, then our inward nature is converted within us and we become wholly of the number of those concerning whom it is written in another Psalm: "All the glory of the daughter of kings is within, in golden borders" (Psalm 45:13).”

“..."Bless the Lord, O my soul! and all that is within me, His holy Name" (ver. 1). I suppose that he speaketh not of what is within the body; I do not suppose him to mean this, that our lungs and liver, and so forth, are to burst forth into the voice of blessing of the Lord. There are lungs in our breast indeed, like a kind of bellows, which send forth successive breathings, which breathing forth of the air inhaled is pressed out into voice and sound, when the words are articulated; nor can any utterance sound forth from our mouth, but what the pressed lungs have given vent to; but this is not the meaning here; all this relateth to the ears of men. God hath ears: the heart also hath a voice. A man speaketh to the things within him, that they may bless God, and saith unto them, "all that is within me bless His holy Name!" Dost thou ask the meaning of what is within thee? Thy soul itself. In saying then, "all that is within me, bless His holy Name," it only repeateth the above, "Bless the Lord, O my soul:" for the word "Bless," is understood. Cry out with thy voice, if there be a man to hear; hush thy voice, when there is no man to hear thee; there is never wanting one to hear all that is within thee. Blessing therefore hath already been uttered from our mouth, when we were chanting these very words. We sung as much as sufficed for the time, and were then silent: ought our hearts within us to be silent to the blessing of the Lord? Let the sound of our voices bless Him at intervals, alternately, let the voice of our hearts be perpetual. When thou comest to church to recite a hymn, thy voice soundeth forth the praises of God: thou hast sung as far as thou couldest, thou hast left the church; let thy soul sound the praises of God. Thou art engaged in thy daily work: let thy soul praise God. Thou art taking food; see what the Apostle saith: "Whether ye eat or drink, do all to the glory of God." I venture to say; when thou sleepest, let thy soul praise the Lord. Let not thoughts of crime arouse thee, let not the contrivances of thieving arouse thee, let not arranged plans of corrupt dealing arouse thee. Thy innocence even when thou art sleeping is the voice of thy soul.”

“Who does not see how impious and how sacrilegious it is if a person, who has been converted to good things through penance for his past evils, believes that there can be no forgiveness for any sin? What else is being done with these words than that the hand of the all-powerful physician is being pushed away by the vice of despair, from effecting human salvation? For the physician himself says, "Those who are healthy do not need a physician, but the sick do." If our physician is an expert, he can cure all maladies. If God is merciful, he can forgive all sins. A goodness that does not conquer every evil is not a perfect goodness, nor is a medicine perfect for which any disease is incurable. It is written in the sacred writings, "Against wisdom, evil does not prevail"; and the omnipotence of our physician is made known by such words in the psalm: "Bless the Lord, O my soul, and all that is within me, bless his holy name. Bless the Lord, O my soul, and do not forget all his benefits—who forgives all your iniquity, who heals all your diseases, who redeems your life from the pit, who crowns you with steadfast love and mercy, who satisfies you with good as long as you live so that your youth is renewed like the eagle's." What, I ask, do we think cannot be forgiven us when the Lord forgives all our iniquities? Or what do we think cannot be healed in us, when the Lord heals all our diseases? Or how is there anything still lacking to the healed and justified person whose desire is satisfied with good things? Or how is he not believed to gain the benefit of complete forgiveness to whom a crown is given together with love and mercy? Therefore, let no one despairing of the physician remain in his infirmity; let no one, downplaying the mercy of God, waste away in iniquities. The apostle calls out that "Christ died for the ungodly."”