John had already mentioned the bottomless pit in Revelation 9:1. This is the abyss where the Lord had chained the angels that joined Satan in the rebellion of the beginning (see Jude 1:6; 2 Peter 2:4). The beast that rises from this pit will receive more attention in Revelation 13:1 (and Revelation 17:8). At this point John provides no further details concerning the nature or identity of this beast and so we do not yet need to know more for an adequate understanding of this paragraph. That said, the fact that this beast arises from the abyss demonstrates that it is an enemy of God and of God’s two witnesses, and so is an unwelcome intruder on the earth where these two witnesses testify.
7 And when they have finished their testimony, the beast that rises from the bottomless pit will make war on them and conquer them and kill them,