“And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works.”
King James Version (KJV)
2:23 And I will kill her children - Those which she hath borne in adultery, and them whom she hath seduced. With death - This expression denotes death by the plague, or by some manifest stroke of God's hand. Probably the remarkable vengeance taken on her children was the token of the certainty of all the rest. And all the churches - To which thou now writest. Shall know that I search the reins - The desires. And hearts - Thoughts.
Re 2:23 I will kill her children with death. Her children are the adherents; those who perpetuate the immoral practices. The threat implies that they shall come to certain destruction. And all the churches shall know that I am he which searcheth the reins and hearts. By reason of the judgments inflicted.