The scriptures read are Ezekiel 43-44, Psalm 89:19-52 and Revelation 13.
Ezekiel 43. Ezekiel sees God's glory enter through the east gate of the temple. He says if his people change their sinful ways, he will dwell with them.
Ezekiel 44. The man showing Ezekiel around says that since God came through the east gate, no one else may use that gate. New regulations are made to keep the old desecrations from being repeated.
Psalm 89:19-52. This version of this psalm almost has an Irish tenor/Irish tune feel to it.
Revelation 13. The dragon calls a beast from the sea and one from the earth and together they form an evil trinity. The sea monster recalls the Leviathan and the land monster the Behemoth (Job 40 & 41). And yet with the 10 horns and seven heads the sea beast resembles some of the beasts of Daniel although as one monstrous mash-up. One of the sea beast's heads has a fatal wound from which it has recovered, a parody of Jesus' death and resurrection. His career runs 3 1/2 years, just like Jesus'.
The beast from the earth is a parody of the Holy Spirit, which is compared to wind and breath. The land beast persuades people to worship the sea beast, like the Holy Spirit testifies to Jesus. He performs miracles, including calling down fire from heaven (remember the incident from Elijah's life?) He marks people with the sign of the beast, just like the seal of God.
The mark is a number: 666. Remember that John is hiding the plain meaning of what he is writing to the church so the authorities won't destroy the record of his visions. Reducing a name to its numerical value was a common way of sending someone a secret message. The most logical candidate for the name that the number encodes is Nero Caesar. If you transliterate his name from Greek (the most widespread language of the empire) into Hebrew and add of the numerical value of the letters (they had no numerals, so aleph (a)=1, bet (b)=2, etc), Nero's name totals 666. (If you transliterate it from Latin, you get 616, which is a variant reading of the text.) There was a rumor afloat that Nero, though dead by his own hand, would come back. And the Emperor Nero considered himself a living god. Remember all that stuff about the cult of emperor worship back in the beginning of this book?
(I'm on the road and didn't bring my other commentary so what the four schools of interpretation make of this will have to wait till tomorrow. But for some of the ideas above I wish to thank The New Bible Commentary from IVP.)