2 Samuel 22:44–51 (ESV)

            “You delivered me from strife with my people;
                        you kept me as the head of the nations;
                        people whom I had not known served me.
            Foreigners came cringing to me;
                        as soon as they heard of me, they obeyed me.
            Foreigners lost heart
                        and came trembling out of their fortresses.  

            “The LORD lives, and blessed be my rock,
                        and exalted be my God, the rock of my salvation,
            the God who gave me vengeance
                        and brought down peoples under me,
            who brought me out from my enemies;
                        you exalted me above those who rose against me;
                        you delivered me from men of violence.        

            “For this I will praise you, O LORD, among the nations,
                        and sing praises to your name.
            Great salvation he brings to his king,
                        and shows steadfast love to his anointed,
                        to David and his offspring forever.”

The first paragraph expresses David’s amazement at an unexpected blessing. In addition to rescuing David and giving him victory in battle, God has blessed David politically. The line, “people whom I had not known served me,” shows that David was surprised by this.

Even foreigners showed amazing, extreme deference. So, what can David do but praise the LORD, my rock, the consistent and unshakeable one.

God’s blessing has been total—salvation, vengeance, elevation, exaltation, and deliverance.

Then we get an electrifying promise, which is veiled in the English translation. David will praise God for yet something else. All the great things David has listed are terrific, “But wait; there’s more!”

Great salvation he brings to his king,
            and shows steadfast love to his anointed,
            to David and his offspring forever.”

The Hebrew words translated as anointed (מְשִׁיחֹ֛ו, mi-she-kho) and offspring (זַרְעֹ֖ו, zar-oh) are both in the singular. They aren’t about all of David’s descendants.

They’re about one person—the Messiah.