David wrote this Psalm before he went out to fight Goliath, it contains all 7 (the number of completion) of the names of God.
The Lord is my shepherd (1. Jehovah-Ro'i, the Lord my Shepherd)
I shall not want (2. Jehovah-Jireh, the Lord my Provider)
He maketh me to lie down in green pastures:
He leadeth me beside the still waters. (3. Jehovah-Shalom, the Lord my Peace)
He restoreth my soul: (4. Jehovah-Rafe, the Lord my Healer)
He leadeth me in paths of righteousness for His name's sake. (5. Jehovah-tsidknu, the Lord my Righteousness)
Yea though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me (6. Jehovah-Shammah, the Lord who is Always There)
Thy rod and thy staff they comfort me. Thou preparedst a table before me in the presence of mine enemies:
Thou anointest my head with oil; my cup runneth over. (7. Jehovah-Nissi, the Lord our Banner)
Surely, Goodness and Mercy shall follow me all the days of my life: and I will dwell in the house of the Lord forever.