At times, the prophets used “David” to refer to David’s descendant, the Messiah. That should not surprise us. Remember that Malachi 4:5 called John the Baptizer “Elijah” because John was like Elijah (Luke 1:13-17; Matthew 11:14). Similarly, David, as the ideal king, was a fitting figure, a symbol that stood for his descendant, the Messiah.
Behold, the days are coming, declares the LORD, when I will raise up for David a righteous Branch, and He shall reign as king and deal wisely, and shall execute justice and righteousness in the land (Jeremiah 23:5 cf. Isaiah 16:5).
They shall serve the LORD their God and David their king, whom I will raise up for them (Jeremiah 30:9 cf. Hosea 3:5).
I will set up over them one shepherd, My servant David, and He shall feed them: He shall feed them and be their shepherd. And I, the LORD, will be their God, and My servant David shall be prince among them. I am the LORD; I have spoken (Ezekiel 34:23-24).
“I will set up over them one shepherd.”
God sometimes had David speak of himself when, by inspiration, he was really speaking about his descendent, Jesus. For example, in Psalm 16:26-27 David seemed to say He would rise from death before His flesh decayed. Quoting that prophecy, Peter pointed out that David’s body remained in its tomb. Peter showed that David was, in fact, predicting Jesus’ resurrection (Acts 2:25-31). Peter concluded,
Let all the house of Israel therefore know for certain that God has made Him both Lord and Christ, this Jesus whom you crucified (Acts 2:36).
Hear again the titles used by Peter and the prophets: Anointed (Messiah, Christ), King, Shepherd, Ruler and Lord! The One God rules through “one Lord.” Jesus is the “one Lord” of unity in Ephesians 4. This unity—unity enjoyed under His reign—was also the subject of prophecy.