Psalm 23 is probably the most popular of all the psalms and is a hymn of God's goodness to his people. God is first portrayed as a shepherd, and then as a king. This psalm has been a source of comfort and encouragement to millions over many times, and today is as fresh and appropriate as David wrote it. Jesus may have been thinking of these or other psalms when he said of himself, "I am the good shepherd."
A shepherd cares for his sheep; he meets all their needs. He guides them to the green pastures with comfortable waters that are symbols of health and freshness. But when God is the shepherd, he will do much more.