yes Earth/world = footstool
Matthew 5:35
or by the earth, for it is his footstool;
And then in hebrews Jesus awaits his enemies becoming his footstool. How can this be?
Revelation 12:9
The great dragon was hurled down—that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him.
Revelation 12:10 (New International Version)
10 Then I heard a loud voice in heaven say:
"Now have come the salvation and the power and the kingdom of our God,
and the authority of his Christ.
For the accuser of our brothers,
who accuses them before our God day and night,
has been hurled down.
Revelation 12:12 (New International Version)
12 Therefore rejoice, you heavens
and you who dwell in them!
But woe to the earth and the sea,
because the devil has gone down to you!
He is filled with fury,
because he knows that his time is short."
Satan is ruler of the world the footstool. It is in that moment that the above scripture declares the salvation now Satan has come down to earth/footstool.
Ephesians 2:2
in which you used to live when you followed the ways of this world and of the ruler of the kingdom of the air, the spirit who is now at work in those who are disobedient.