"The Lord is my shepherd, I lack nothing." NIV translation
We remember that, before David was made king over Israel, he was a lowly shepherd boy and knew what it meant to be a shepherd. A shepherd is responsible for making sure that his flock gets the food and water that it needs as well as making sure that they are safe from predators. Sheep are not smart animals and they are defenseless and so they require constant care. Surely there were times in his life when David must have felt as helpless as a sheep as he faced enemies and wars on every side. Looking back on those years, he says that the Lord has been there through it all and provided for his needs.
We can find comfort in the fact that we are a part of the same flock as King David and, just as the Lord was with him through it all, we are assured that the Lord will be with us as well. Our "through it all" may be quite different than David's but, whatever we face, God is bigger than the situation.
"He makes me lie down in green pastures, he leads me beside quiet waters," NIV translation
The daily life for a shepherd required getting up early in the morning and leading the flock to a place where they could eat and drink. Sheep do not like to drink from water that is moving but prefer calm pools of water. This is because they cannot swim and when their wool gets soaked it becomes very heavy and could cause them to drown. As David reflects back on his life, he remembers that the Lord has always provided for his physical needs.
"he refreshes my soul. He guides me along the right paths for his name's sake." NIV translation
After the sheep were fed and watered, they would lie down and rest through the hottest part of the day. The shepherd had to know the way to the places where all of this could be found as, without him, the sheep would just wander around until they died of thirst or were killed by predators. Now, looking back, David reflects on the fact that the Lord had guided him throughout his life and protected him. He was known as a man that followed the Lord and so his life worked to bring glory to God.
In the same way, our lives can serve to bring glory to the name of the Lord. People are constantly watching and, when they see us following the Lord and His excellent care for us, it brings glory to His name.
"Even though I walk through the darkest valley, I will fear no evil, for you are with me; your rod and your staff they comfort me." NIV translation
We remember that this song was written near the end of David's life and he has reflected on what the Lord had done for him in the past. Now, he turns to the fact that his time on this earth is coming to an end.
The shepherd used the rod to fend off predators and the staff was used to rescue the sheep if they were to fall into a hole or some other calamity. David had the assurance of the Lord's protection and guidance so he could face this time without fear. Once again, the Lord had been with him "through it all" and so he could expect that the Lord will be with him now as well. That same assurance is ours if we remember that, through Jesus Christ, we are a part of the same flock as King David.
"You prepare a table before me in the presence of my enemies. You anoint my head with oil; my cup overflows." NIV translation
David reflects on the fact that the Lord has provided for him even as he faces the end of his life. While many people had wished him harm and Satan had even tempted him to fall, the Lord had still provided a way for his salvation.
The shepherd would put olive oil on the head of his sheep to protect them from flies and also from poisonous snakes that would pop out of holes in the ground and bite them on the nose as they grazed. The olive oil was also used for healing sick sheep and the shepherd would carry a cup that would be used to dip water out of the pool to water the sick sheep. David is confident that he is prepared for whatever he would face upon his death.
In the same manner, we are anointed with the Holy Spirit and can know that we are prepared for that step from this world to an eternity with our Lord and Savior.
"Surely your goodness and love will follow me all the days of my life, and I will dwell in the house of the Lord forever." NIV translation
David ends with the confidence of being in the presence of God for eternity. As he had reflected on the fact that the Lord had been with him in his past earthly struggles and in his present as he came to terms with his own pending death, he was sure that the Lord would continue to guide him to his rest in the future of eternity.