Seven hundred seventy-seven
In Genesis 5:31, this signifies the vastation of this last generation of the Most Ancient Church when all that was holy with them was consummated. (Arcana Coelestia 728)
Revelation 11:2
2
Leave out the court which is outside of the temple, and don't measure it, for it has been given to the nations. They will tread the holy city under foot for forty-two months.