Taha 20:76

Jannatu AAadnin tajree min tahtihaal-anharu khalideena feeha wathalikajazao man tazakka

Gardens of perpetual residence beneath which rivers flow, wherein they abide eternally. And that is the reward of one who purifies himself.

the eternal gardens beneath which rivers flow, in which they shall live for ever. That is the reward for the one who has purified himself.