Deuteronomy 8:20
As the nations which the Lord destroyeth before your face, so shall ye perish; because ye would not be obedient unto the voice of the Lord your God.
Cross-reference
Deuteronomy 7:23 describes God giving the nations over to destruction—the same fate Israel will suffer for disobedience.
Deuteronomy 11:17 warns that disobedience will cause Israel to perish quickly—a parallel warning within the same book.
Deuteronomy 30:18 echoes the same warning of perishing for disobedience, reinforcing the covenant curse.
2 Chronicles 36:17 records Babylon's destruction of Jerusalem—the fulfillment of the warning that Israel would perish like the nations.
Daniel 9:11 confesses that the curse from the Law of Moses has been poured out—directly referencing the covenant curses.
Daniel 9:12 confirms that God has brought the great calamity he spoke against Jerusalem—fulfilling the warning of perishing.
2 Kings 18:12 records Israel's destruction for not obeying, fulfilling the warning here.
2 Chronicles 36:16 describes mocking prophets until wrath has no remedy—an example of the disobedience leading to perishing.