Albert Barnes Commentary 1 Chronicles 29:23

"Then Solomon sat on the throne of Jehovah as king instead of David his father, and prospered; and all Israel obeyed him." — 1 Chronicles 29:23 (ASV)

The throne of David is called here “the throne of the LORD,” just as in 1 Chronicles 28:5 it is called “the throne of the kingdom of the LORD,” because God had set it up and had promised to establish it.