4 We therefore trust without fear on the word of Him who cannot deceive. “My soul has trusted in the Lord, from the morning watch even unto night”. This morning watch is the end of night. We must therefore understand it so that we may not suppose we are to trust in the Lord for one day only. What do you conceive to be the sense, then, brethren? The words mean this: that the Lord, through whom our sins have been remitted, arose from the dead at the morning watch, so that we may hope that what went before in the Lord will take place in us. For our sins have been already forgiven: but we have not yet risen again: if we have not risen again, not as yet has that taken place in us which went before in our Head. What went before in our Head? Because the flesh of that Head rose again; did the Spirit of that Head die? What had died in Him, rose again. Now He arose on the third day; and the Lord as it were thus speaks to us: What you have seen in Me, hope for in yourselves; that is, because I have risen from the dead, you also shall rise again.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)