As 1 Samuel 16:1–13 reveals, nothing in David himself made him worthy of the throne of Israel. The lineage of his father Jesse is not given in detail, which is the author’s way of depicting the clan’s insignificance. David was also the youngest son of Jesse, perhaps as young as eleven or twelve at his anointing, and one whom Jesse hardly regarded as a possible candidate for king (vv. 11–12). True, David had rugged good looks (v. 12), but he was certainly not the only handsome shepherd boy in the land.
Because David was finally unworthy of the throne, he and his sons were to understand that they relied on God alone for their position and were to trust Him to keep His promises. David’s family had difficulty grasping this truth, but it was not a problem for Ethan the Ezrahite, the author of Psalm 89. This psalm celebrates the Davidic covenant, even fleshing out its blessings more fully than 2 Samuel 7 or 1 Chronicles 17.
We see in Psalm 89 that our Creator’s bond with David is no ordinary covenant, for in it the Lord is pleased to share His sovereignty. One commentator demonstrates how if we compare what is said about the Davidic king with what is said about God, we find parallels in which He and David are similarly described. Just as the Lord is exalted (vv. 16–18), so too is David’s throne exalted (v. 19). Note also that God crushes all His foes (vv. 9–10) even as David’s enemies will be crushed before him (vv. 22–23). Furthermore, the Lord is the supreme ruler over all (vv. 5–12) and the Davidic king is “the highest of the kings of the earth” (vv. 2 4–27).
Unlike David and all but one of his sons, however, God is inherently worthy of all these honors. Still, the Lord graciously promised never to turn His back on David’s line completely. He confirmed this love with an oath, which He swore by His holiness, for He can swear by none higher (vv. 35–37; see Heb. 6:13).
Yet one of David’s sons is worthy to share honor with God, and our Creator ultimately gives glory to this Son alone. This one bore the rod for the sins of David’s people in a way David and his other sons never could (Ps. 89:30–34). David and his sons were promised blessing, but as John Calvin writes, “In the branch which sprung from the root of Jesse, these words were fulfilled in their fullest sense.” Jesus Christ, the incarnate God, son of David, and branch of Jesse, alone can share His Father’s glory.