2 Chronicles 6:16
Now therefore, O LORD God of Israel, keep with thy servant David my father that which thou hast promised him, saying, There shall not fail thee a man in my sight to sit upon the throne of Israel; yet so that thy children take heed to their way to walk in my law, as thou hast walked before me.
This verse belongs to Solomon's prayer spoken vocally at the dedication after the temple was finished and erected. It was offered kneeling on a brazen scaffold before the altar in the presence and hearing of all the congregation of Israel with hands spread toward heaven, and its words are preserved in the Bible. In that prayer Solomon declared that there is no God like the Lord in heaven or earth, who keeps covenant and shows mercy to servants who walk before Him with all their hearts. He acknowledged that God had kept with David what He promised and fulfilled by His hand what He spoke by His mouth. The verse then asks God to keep and verify the promise made to David his father that he shall never lack a man in God's sight to sit on the throne of Israel, presenting a dynastic promise within Israel's covenant relationship with God.
The promise is conditional, applying only as David's children take heed to their way to walk in God's law as David walked before Him. The petition is joined to the confession that God cannot in very deed be contained by an earthly house, since heaven and the heaven of heavens cannot contain Him. This taught that He is not confined to the temple and His people may worship Him wherever they are. It is joined also to the plea that He regard His servant's prayer, keep His eyes open day and night on the house where He put His name, hearken to prayer made toward that place, and hear from His dwelling in heaven and forgive His servant and His people Israel.
The prayer containing the verse was marked by deep humility and devotion. After the prayer ended, fire was sent from heaven and consumed the burnt offering, and God appeared to Solomon by night to say that He had heard his prayer.