I was then given a stick that looked like a measuring-rod, and was told, "Go and measure the temple of God and the altar, and count those who are worshiping in the temple. 1
References for Revelation 11:1
11.1 Ez 40.3; Zec 2.1, 2.
But do not measure the outer courts, because they have been given to the heathen, who will trample on the Holy City for forty-two months. 2
References for Revelation 11:2
I will send my two witnesses dressed in sackcloth, and they will proclaim God's message during those 1,260 days."
The two witnesses are the two olive trees and the two lamps that stand before the Lord of the earth. 3
References for Revelation 11:4
11.4 Zec 4.3, 11-14.
If anyone tries to harm them, fire comes out of their mouths and destroys their enemies; and in this way whoever tries to harm them will be killed.
They have authority to shut up the sky so that there will be no rain during the time they proclaim God's message. They have authority also over the springs of water, to turn them into blood; they have authority also to strike the earth with every kind of plague as often as they wish. 4
References for Revelation 11:6
11.6 a 1 K 17.1; b Ex 7.17-19; c 1 S 4.8.