2 Chronicles 7:20
Then will I pluck them up by the roots out of my land which I have given them; and this house, which I have sanctified for my name, will I cast out of my sight, and will make it to be a proverb and a byword among all nations. Then will I pluck them up by the roots out of my land which I have given them; and this house, which I have sanctified for my name, will I cast out of my sight, and will make it to be a proverb and a byword among all nations.
This was God's conditional answer to Solomon after the seven days spent dedicating the finished temple, when fire came down from heaven and the glory of the Lord filled the house. He had hallowed the house to put His name there forever, with His eyes and His heart there perpetually. On the positive side, if Solomon walked before Him as David had walked in integrity of heart and uprightness, and kept all His commandments, statutes and judgments, He would establish the throne of Israel forever. Then the glorious building would stand forever in all its splendor as a perpetual sign of special favor and as evidence of the prosperity and exalted blessings resting on the people who alone preserved true worship by keeping His commandments. This showed He is not confined to a built temple like heathen gods, yet He would meet His people by His Spirit in the dedicated house while they remained faithful and true.
The warning was that if Israel or their children turned from following Him, forsook His commandments, and served and worshiped other gods, He would pluck them up by the roots and remove them out of the land He had given them. He would cast the house sanctified for His name out of His sight and reject it from His presence, and Israel and the temple would become a proverb and a byword among all nations and a public warning. The ruin of the temple would astonish passersby, and the stated reason for the judgment would be that Israel had forsaken the God who brought their ancestors out of Egypt and had served other gods.
God's promises of prosperity and Israel's possession of the land and the temple's continuing place and standing as a sign of His favor depended on and were conditional on faithful obedience. Those who abandon His way bring ruin on themselves and on those who look to them for guidance. This warning belongs together with His promise to hear, forgive, and heal when His people humble themselves, pray, seek Him, and turn from wickedness.
The conditional threat was fulfilled some hundreds of years, or centuries, after the temple was built because Israel transgressed the commandments, committed wicked acts, sinned and turned from God. God let the people go into captivity to humble and punish them and let the temple be destroyed. Before the destruction He told a few faithful servants the fate of the temple, which had become the pride of Israel and was regarded with idolatry while they were sinning against God, and revealed to them the captivity of Israel. Just before the destruction those righteous men removed the sacred ark containing the tables of stone and with mourning hid it in a cave from Israel because of their sins, never to be restored to them, and that ark remains hidden and undisturbed.