Jeremiah 3:16
And it shall come to pass, when ye be multiplied and increased in the land, in those days, saith the LORD, they shall say no more, The ark of the covenant of the LORD: neither shall it come to mind: neither shall they remember it; neither shall they visit it; neither shall that be done any more.
When the people are multiplied and increased in the land, in those days they shall say no more concerning the ark of the covenant, neither shall it come to mind, nor shall they remember it, nor seek it, nor visit it. This belongs to a restoration in which Jerusalem is called the throne of the Lord and the nations gather to it. In that gathering is seen God's plan for the gospel to spread outward from Israel to all nations.
Before the temple was destroyed and Israel went into captivity for its sins, faithful men hid the sacred ark containing the tables of stone in a cave. There it remained hidden and undisturbed. The ark was never restored to Israel, and its lasting absence because of Israel's sins fulfilled the prediction.