Psalms

Two-edged swords (149:6) were made of bronze or iron and were filed on each side, so that the blade could more readily and deeply penetrate enemy armor. In the NT, the word of God is said to be “sharper than any two-edged sword” (Heb. 4:12) because of the way it exposes the deepest “thoughts and intentions” of a person’s heart.
Who are the saints? The term “saints” is used in both the OT and NT to describe God’s people. In the OT it describes the faithful among God’s people Israel (37:28; 145:10). In the NT, the Greek word translated “saints” means “holy,” in the sense of being set apart for God. This includes all those, no matter what their background, who have put their trust in Jesus, the only one who can truly make them holy.
In the OT, salvation generally refers to deliverance from both physical and spiritual danger. Because God had been a faithful Savior in the past, Israel trusted that they could look forward to his greater salvation in the future. The ultimate salvation for all mankind would come through Jesus the Messiah.
The Lord protects his people. Psalm 138 tells of God’s constant care for everyone who loves him. Singing this psalm helps believers be more aware of the ways in which God preserves and protects them.
Wonders can also be translated “marvels.” The word is often used to describe God’s works of rescuing his people and protecting and caring for them (9:1; 78:11; 98:1; Ex. 3:20; 34:10). In Ps. 136:4, it describes creation, showing that God’s work as Creator should fill us with awe and wonder.
What is “renown”? The word “renown” refers to being well-known or specially honored. In 135:13, it could also mean a “remembrance.” Psalm 135 echoes the words of Ex. 3:15: “This is my name forever, and thus I am to be remembered throughout all generations.”
Anointing with oil. It was common during festivals for people to have their foreheads anointed with fragrant oils. This not only provided a pleasant aroma but gave the person a glistening look of good health. (See 133:2.)