He that hath an ear, let him hear,....See Gill on "Re 2:7";he that overcometh; and is not intimidated by poverty, confiscation of goods, tribulation, persecution, and death itself, but through Christ is a conqueror, and more than a conqueror over all these things:shall not be hurt of the second death; by which is meant eternal death, in distinction from a corporeal and temporal one; and lies in a destruction of both body and soul in hell, and in an everlasting separation from God, and a continual sense of divine wrath; but of this the saints shall never be hurt, they are ordained to eternal life; this is secured for them in Christ, and he has it in his hands for them, and will give it to them.
The phrase is Jewish, and is opposed to the first death, or the death of the body; which is the effect of sin, and is appointed of God, and which the people of God die as well as others; but the second death is peculiar to wicked men.
So the Jerusalem Targum on De 33:6; paraphrases those words, "let Reuben live, and not die", thus;"let Reuben live in this world, and not die anyynt atwmb, "by the second death", with which the wicked die in the world to come.'
'Of which sense of the text and phrase Epiphanius makes mention . See the same phrase in the Targum of Jonathan ben Uzziel, in Isa 22:14; and in Jer 51:39; and in Philo the Jew . Contr. Haeres. Haeres.
9. De Praemiis & Poenis, p.