وَلَا تَفْنَيَانِ وَلَا يَفْنَى أَهْلُهُمَا
Paradise and Hell will not perish, nor will their inhabitants cease to exist.
Their permanence is by God's sustaining will; a created thing's continued existence is not the same as God's uncreated eternity and necessity. Something that began to exist can be preserved indefinitely.
Thus permanence into the future must be distinguished from existence without a beginning.