11 “Shall your wondrous works be known in the dark, and your righteousness in the land where all things are forgotten?”, the dark answers to the land of forgetfulness: for the unbelieving are meant by the dark, as the Apostle says, “For you were sometimes darkness;” and the land where all things are forgotten, is the man who has forgotten God; for the unbelieving soul can arrive at darkness so intense, “that the fool says in his heart, There is no God.” Thus the meaning of the whole passage may thus be drawn out in its connection: “Lord, I have called upon You,” amid My sufferings; “all day I have stretched forth my hands unto You”.
I have never ceased to stretch forth My works to glorify You. Why then do the wicked rage against Me, unless because “Thou showest not wonders among the dead”? Because those wonders move them not to faith, nor can physicians restore them to life that they may praise You, because Your hidden grace works not in them to draw them unto believing: because no man comes unto Me, but whom You have drawn. Shall then “Your loving-kindness be showed in the grave”? That is, the grave of the dead soul, which lies dead beneath the body's weight: “or Your faithfulness in destruction”?
That is, in such a death as cannot believe or feel any of these things. “For how then in the darkness” of this death, that is, in the man who in forgetting You has lost the light of his life, “shall Your wondrous works and Your righteousness be known.”...
Source: The Enarrations, or Expositions, on the Psalms (New Advent)