Salmos 51
Bede
Salmos 51:10
Let us call to mind that he promised that [Jesus] would send the grace of the Spirit to his disciples, and he did send it. And let us take care with all watchfulness, lest by our seductive thoughts we grieve the Holy Spirit of God, in whom we have been sealed for the day of redemption. For so it is written, "The Holy Spirit will flee the pretense of discipline, and will remove himself from thoughts that are without understanding." When the psalmist was burning with the desire to receive this Spirit, he providently sought first [to have] the guest chamber of a clean heart in which he could receive him, and so at length [he] sought the entry of so great a guest. "Create a clean heart in me, O God," he said, "renew an upright spirit in my inmost parts." He entreated that first a clean heart be created in him and then that an upright spirit be renewed in his inmost parts, because he knew that an upright spirit could have no place in a defiled heart. — Homilies on the Gospels 2:11
Salmos 51:10
It is only by participation in the divine goodness that a rational creature is recognized as being capable of becoming good. Hence the Lord also bears witness by a benevolent promise that "your Father from heaven will give his good Spirit to those who ask him." This is to point out that those who of themselves are evil can become good through receiving the gift of the Spirit. He pledged that his good Spirit would be given by the Father to those asking for him, because whether we desire to secure faith, hope and charity, or any other heavenly goods at all, they are not bestowed on us in any other way than by the gift of the Holy Spirit. So it is that the same Spirit, in Isaiah, is named the Spirit of wisdom and understanding, the Spirit of counsel and fortitude, the Spirit of knowledge and piety, the Spirit of the fear of the Lord; and in another place, the Spirit of love and peace [and] the Spirit of grace and prayers. Undoubtedly whatever good we truly have, whatever we do well, this we receive from the lavishness of the same Spirit. When a prophet who understood this was seeking purity of heart, saying, "Create a pure heart in me, O Lord," he immediately added, "Renew a steadfast spirit within me." If the steadfast Spirit of the Lord does not fill our innermost being, we have no pure heart where he may abide. When in his eager longing for an advance in good for his work he had said, "Lord, I have had recourse to you, teach me to do your will," he at once showed in what way he had to secure this when he went on, "Let your good Spirit lead me into the right way." — Homilies on the Gospels 2:14