David brings the Ark of the Covenant up to Jerusalem, and the first attempt goes badly wrong — Uzzah reaches out to steady it on a cart and is struck down for touching what the law had always said only Levites, carrying it by its poles, were permitted to touch (2 Samuel 6:6–7; compare Numbers 4:15). David is furious and afraid in the same breath, and it takes three months before he tries again, this time doing it the way the law actually specified. When the Ark finally enters the city, David dances before it "with all his might," stripped down to a linen ephod, and his wife Michal watches from a window and despises him for it (2 Samuel 6:14–16). Notice the contrast the text is drawing: Michal, Saul's daughter, cares about royal dignity; David cares about being seen worshipping honestly, even if it costs him some. That's worth sitting with, because it's the same posture you'll find at the center of his psalms.
Then comes the hinge of David's entire story. He wants to build God a permanent house, a temple to replace the tent the Ark has lived in since the wilderness. God's answer, through the prophet Nathan, refuses the offer and reverses it entirely: "the LORD telleth thee that he will make thee an house... I will set up thy seed after thee... and I will establish the throne of his kingdom for ever" (2 Samuel 7:11–13). Read that carefully — David wanted to build God a house; God tells him instead that He will build David a house, a dynasty, and that this throne will stand forever. This is the Davidic covenant, unconditional in a way the earlier covenants with Israel at Sinai weren't, and it is the single verse the rest of Scripture keeps circling back to whenever it talks about a coming king. David's response is a prayer almost startled by its own scale: "who am I, O Lord GOD? and what is my house, that thou hast brought me hitherto?" (2 Samuel 7:18).
Worth knowing here too: in 1993, an inscribed stone fragment was discovered at Tel Dan referring to the "House of David" — the first and still most significant extra-biblical evidence confirming David wasn't a later national myth invented to dignify the monarchy, but a real founding figure whose dynasty was known and named by neighboring, hostile kingdoms within a couple of centuries of his death. Lennox's whole case for historically grounded faith leans on exactly this kind of find — not proof of every detail, but solid ground under the claim that Genesis-through-Kings is remembering something real.