“for then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be. And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened. Then if any man shall say unto you, Lo, here is Christ, or there; believe it not. For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.”
Matthew 24:21-24 KJV
https://bible.com/bible/1/mat.24.21-24.KJV
Jeremiah 29
English Standard Version
Jeremiah's Letter to the Exiles
29 These are the words of the letter that Jeremiah the prophet sent from Jerusalem to the surviving elders of the exiles, and to the priests, the prophets, and all the people, whom Nebuchadnezzar had taken into exile from Jerusalem to Babylon. 2 This was after King Jeconiah and the queen mother, the eunuchs, the officials of Judah and Jerusalem, the craftsmen, and the metal workers had departed from Jerusalem. 3 The letter was sent by the hand of Elasah the son of Shaphan and Gemariah the son of Hilkiah, whom Zedekiah king of Judah sent to Babylon to Nebuchadnezzar king of Babylon. It said: 4 “Thus says the Lord of hosts, the God of Israel, to all the exiles whom I have sent into exile from Jerusalem to Babylon: 5 Build houses and live in them; plant gardens and eat their produce. 6 Take wives and have sons and daughters; take wives for your sons, and give your daughters in marriage, that they may bear sons and daughters; ...