Here's another Old Testament reference to the Tribulation I've just found.

Jeremiah 30:7  Alas! for that day is great, so that none is like it: it is even the time of Jacob's trouble, but he shall be saved out of it. 

Here's another Old Testament reference to the Tribulation I've just found. (Jacob's trouble)

Jeremiah 30:7  Alas! for that day is great, so that none is like it: it is even the time of Jacob's trouble, but he shall be saved out of it.