If you are wondering how Daniel 7 ties into Paul’s discussion of the Man of Sin in 2 Thessalonians 2:1-12, then you need to read this post before you continue. That post will explain why I think Daniel 7 is important in understanding the Man of Sin.
In this chapter Daniel has a vision, which he then records for us. The vision is of a Great Sea and Four Beasts coming from the Sea. When interpreting the dream Daniel states that the beasts refer to four kingdoms (7:17 compared with 23).