2 Chronicles 6:10
The Lord therefore hath performed his word that he hath spoken: for I am risen up in the room of David my father, and am set on the throne of Israel, as the Lord promised, and have built the house for the name of the Lord God of Israel.
Cross-reference
2 Chronicles 6:4 is Solomon's opening blessing that God fulfilled his word, while verse 10 gives the specific fulfillment — sitting on throne and building the temple.
2 Chronicles 1:1 describes Solomon's strengthened kingdom and God's presence, supporting his claim in 6:10 that he sits on David's throne.
1 Kings 2:12 records Solomon sitting on David's throne, the very event he references as God's fulfilled promise in 2 Chronicles 6:10.
1 Chronicles 17:11 is God's promise that David's son would succeed him — here Solomon declares that promise fulfilled.
1 Chronicles 28:5 records David announcing God's choice of Solomon as king — here Solomon speaks of that choice being realized.
1 Chronicles 29:23 records Solomon sitting on the throne — the same event he references here as God's fulfilled promise.
Ecclesiastes 2:18 expresses despair over leaving a legacy to a successor — here Solomon joyfully receives the throne from David. Contrast in tone.
Ecclesiastes 2:19 worries about an unworthy heir — here Solomon celebrates God's faithfulness in giving him the throne. Contrast between receiving and bequeathing.
In 1 Kings 3:7, Solomon prays for wisdom after becoming king — here he declares the same succession fulfilled, but there he acknowledges his youth.