Adam Clarke on Revelation 21:4

There shall be no more death - Because there shall be a general resurrection. And this is the inference which St Paul makes from his doctrine of a general resurrection, 1Cor 15:26, where he says, "The last enemy that shall be destroyed is death." But death cannot be destroyed by there being simply no farther death; death can only be destroyed and annihilated by a general resurrection; if there be no general resurrection, it is most evident that death will still retain his empire. Therefore, the fact that there shall be no more death assures the fact that there shall be a general resurrection; and this also is a proof that, after the resurrection, there shall be no more death. See the whole of the note on 1Cor 15:27.