1 Kings 2:4

2:4 and the Lord will fulfill his promise to me, ‘If your descendants watch their step and live faithfully in my presence with all their heart and being, then,’ he promised, ‘you will not fail to have a successor on the throne of Israel.’

1 Kings 8:25

8:25 Now, O Lord, God of Israel, keep the promise you made to your servant, my father David, when you said, ‘You will never fail to have a successor ruling before me on the throne of Israel, provided that your descendants watch their step and serve me as you have done.’