26 “Forsake me not, O Lord; O my God, depart not from me”. Let us speak in Him, let us speak through Him (for He Himself intercedes for us), and let us say, “Forsake me not, O Lord my God.” And yet He had said, “My God! My God! Why have You forsaken Me?” and He now says, “O My God, depart not from Me.” If He does not forsake the body, did He forsake the Head? Whose words then are these but the First Man's? To show then that He carried about Him a true body of flesh derived from him, He says, “My God, My God why have You forsaken Me?” God had not forsaken Him. If He does not forsake You, who believest in Him, could the Father, the Son, and the Holy Ghost, One God, forsake Christ? But He had transferred to Himself the person of the First Man. We know by the words of an Apostle, that “our old man is crucified with Him.” We should not, however, be divested of our old nature, had He not been crucified “in weakness.” For it was to this end that He came that we may be renewed in Him, because it is by aspiration after Him, and by following the example of His suffering, that we are renewed. Therefore that was the cry of infirmity; that cry, I mean, in which it was said, “Why have You forsaken Me?” Thence was it said in that passage above, “the words of mine offenses.” As if He were saying, These words are transferred to My Person from that of the sinner.
27. “Depart not from me. Make haste to help me, Lord of my salvation”. This is that very “salvation,” Brethren, concerning which, as the Apostle Peter says, “Prophets have enquired diligently,” and though they have enquired diligently, yet have not found it. But they searched into it, and foretold of it; while we have come and have found what they sought for. And see, we ourselves too have not as yet received it; and after us shall others also be born, and shall find, what they also shall not receive, and shall pass away, that we may, all of us together, receive the “penny of salvation in the end of the day,” with the Prophets, the Patriarchs, and the Apostles. For you know that the hired servants, or labourers, were taken into the vineyard at different times; yet did they all receive their wages on an equal footing. Apostles, then, and Prophets, and Martyrs, and ourselves also, and those who will follow us to the end of the world, it is in the End itself that we are to receive everlasting salvation; that beholding the face of God, and contemplating His Glory, we may praise Him for ever, free from imperfection, free from any punishment of iniquity, free from every perversion of sin: praising Him; and no longer longing after Him, but now clinging to Him for whom we used to long to the very end, and in whom we did rejoice, in hope. For we shall be in that City, where God is our Bliss, God is our Light, God is our Bread, God is our Life; whatever good thing of ours there is, at being absent from which we now grieve, we shall find in Him. In Him will be that “rest,” which when we “call to remembrance” now, we cannot choose but grieve. For that is the “Sabbath” which we “call to remembrance;” in the recollection of which, so great things have been said already; and so great things ought to be said by us also, and ought never to cease being said by us, not with our lips indeed, but in our heart: for therefore do our lips cease to speak, that we may cry out with our hearts.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)