Perhaps the most remarkable part of the "key of the house of David" is the ownership of David's throne. This verse records that, after David's death, "Solomon sat on the throne of the LORD as king instead of David his father." David and Solomon sat on God's throne!
The Queen of Sheba provides a second witness to this incredible truth. This apparently Gentile woman understood an important fact about Solomon's throne: "Blessed be the LORD your God, who delighted in you, setting you on His throne to be king for the LORD your God!" (II Chronicles 9:8).
Remarkably, God twice refers to David's throne as His own. It is God's in the sense that Christ will eventually inherit it. Christ, "the Son of David, the Son of Abraham" (Matthew 1:1), will return to earth, claiming His rightful place as "King over all the earth" (Zechariah 14:9). In Isaiah 9:6-7, the prophet Isaiah writes of the "Prince of Peace" who will eventually sit on David's throne:
For unto us a Child is born, unto us a Son is given; and the government will be upon His shoulder. . . . Of the increase of His government and peace there will be no end, upon the throne of David and over His kingdom, to order it and establish it with judgment and justice from that time forward, even forever.
This Child, this Son, whom we know is Jesus Christ, is the Shiloh of Genesis 49:10. There, Jacob prophesies that "to Him shall be the obedience of the people." Christ is of the lineage of David (Luke 3:23-31); He will ultimately sit on David's throne—forever.
Searching for Israel (Part Four): The Kingdom and the Key