The speaker of this psalm begins with a metaphor that acknowledges the dominion his God has over him. In calling the Lord his shepherd, he is recognizing not only the superiority of the Lord to human beings, but also the protection that such a relationship implies. This protection becomes contractual with an obligation on the part of God to provide for all necessities of the speaker in exchange for the speaker’s faithful belief and worship.
Continuing the shepherd metaphor, the speaker explains how the Lord guides him to green pastures and still waters to provide sustenance for his soul in the way that a shepherd literally tends to his flock of sheep by leading them fertile fields and water for food and drink. He also credits the Lord for leading him to the path of righteous behavior and keeping him away from those things forbidden by law in the Hebrew bible. Worth nothing is that this movement toward righteousness is specifically credited with being done for the sake of the Lord’s name and not the man. This detail is significant as it situates faith and worship in the God of Abraham as acceptance of His supreme power and acknowledgment of His abundant love. In other words, simply to follow the Lord is to follow the path of righteousness; the two things are inextricable and interchangeable.
It is a question of trust which the next line directly addresses when the speaker asserts that even when he walks through the valley of the shadow of death, he does so without fear of the evil lurking in those shadows because he has put his faith in God that God will lead him only to the path of righteousness and therefore will be there to protect him even in the darkest places where evil is strongest. Returning to the controlling metaphor, he acknowledges understanding that God will be there protecting him with a rod and staff the way a shepherd uses those instruments to keep predatory danger away from his flock.
The metaphor suddenly shifts to that of God as a host preparing a feast to meet the speaker’s earthly hunger and anointing his head with oil as an act of purification to satisfy his spiritual hunger. Like a family member at the Thanksgiving dinner table, the speaker announces his hunger is completely satisfied: “my cup runneth over.”
This satisfaction of feeling full does not dissipate in mere hours like a Thanksgiving guest, however. The speaker is satiated with the love and protection of the Lord that he is filled with boundless confidence and optimism it will last for as long as he lives. Or at least for as long as he decides to keep his faith in God and remain steadfast among his flock rather than making a run in search of greener pastures.
