2 And why did he say:— From Adam unto Moses did Death rule? And who is so ill-furnished with knowledge as to imagine that only from Adam to Moses has death had dominion? Yet let him understand from this that he said:— Upon all men it passed. Thus, upon all men it passed from Moses until the world shall end. Yet Moses preached that its kingdom is made void. For when Adam transgressed the commandment whereby the sentence of death was passed upon his progeny, Death hoped that he would bind fast all the sons of man and would be king over them for ever.
But when Moses came, he proclaimed the resurrection, and Death knew that his kingdom is to be made void. For Moses said:— Reuben shall live and not die, and shall be in number. And when the Holy One called Moses from the bush he said thus to him:— I am the God of Abraham, of Isaac, and of Jacob. When Death heard this utterance, he trembled and feared and was terrified and was perturbed, and knew that he had not become king for ever over the children of Adam.
From the hour that he heard God saying to Moses:— I am the God of Abraham, of Isaac, and of Jacob, Death smote his hands together, for he learned that God is King of the dead and of the living, and that it is appointed to the children of Adam to come forth from his darkness, and arise with their bodies. And observe that our Redeemer Jesus also, when He repeated this utterance to the Sadducees, when they were disputing with Him about the Resurrection of the dead, thus said:— God is not (God) of the dead, for all are alive unto Him.
Source: Demonstrations (New Advent)