And I will kill her children with death; and all the churches shall know that I am he who searches the minds and hearts: and I will give unto every one of you according to your works.
All Commentaries on Revelation 2:23 Go To Revelation 2
Cyprian of Carthage
AD 258
Nor let any one of you be saddened as if he were inferior to those who before you have suffered tortures, have overcome the world and trodden it under foot, and so have come to the Lord by a glorious road. For the Lord is the "searcher out of the reins and the hearts.".
Also in the Apocalypse: "And all the churches shall know that I am the searcher of the reins and heart; and I will give to every one of you according to his works."