Question: What did the Prophet Jeremiah (and Lehi) prophesy would happen to Judah if they did not repent, and if King Zedekiah rebelled against Babylonian rule and made an alliance with Egypt?
Answer: Jeremiah prophesied that attempts to form a union with Egypt would lead to the destruction of Jerusalem and the holy temple. Jeremiah and Lehi both foretold of Babylonian captivity for the people of Judah unless they repented and turned from their evil ways.
Lehi prophesied, “Wo, wo, unto Jerusalem, for I have seen thine abominations. Yea, and many things did my rather read concerning Jerusalem–that it should be destroyed, and the inhabitants thereof; many should perish by the sword, and many should be carried away captive into Babylon.”
A few years after Lehi left Jerusalem, Zedekiah rebelled against Babylon. Zedekiah’s rebellion took place on the promise of Egyptian support, but before that support arrived at Jerusalem, Nebuchadnezzar reacted to the rebellion by sending an army to camp outside the walls of Jerusalem. After a long siege in which many died, the Holy City fell to Babylon, and many were taken captive. King Zedekiah was killed, and all of his sons killed except Mulek. Mulek escaped execution and later took a group of followers from Jerusalem to the Americas.
A few years after Lehi’s family arrived in the Promised Land and before Lehi died, he told his family, “I have seen a vision, in which I know that Jerusalem is destroyed; and had we remained in Jerusalem we should also have perished.” (2 Nephi 1:4)
Source: 400 Questions and Answers About the Book of Mormon by Susan Easton Black, p 50-51.