No longer will a nursing infant live but a few days, or an old man fail to live out his years. For the youth will die at a hundred years, and he who fails to reach a hundred will be considered accursed.
If these promises were in part fulfilled when the Jews, after their return out of captivity, were settled in peace in their own land and brought as it were into a new world, yet they were to have their full accomplishment in the gospel church, militant first and at length triumphant. The Jerusalem that is from above is free and is the mother of us all.
Commenting on Isaiah 65:17-25
There shall be no more thence an infant of days,.... That is, there shall no more be carried out from thence, from Jerusalem, or any other place where the church of God is, to the grave, in order to be interred, an infant that has lived but a few days, a very common thing now; but, in the latter day, such instances will be rare...
The longevity of men in the first age of the world shall be enjoyed again. thence--from that time forward. infant of days--that is, an infant who shall only complete a few days; short-lived. filled . . . days--None shall die without attaining a full old age. child . . . die . . . hundred years--that is "he that dieth an hundred years old shall die a mere child" [LOWTH].