Az-Zumar 39:20

Lakini allatheena ittaqawrabbahum lahum ghurafun min fawqiha ghurafun mabniyyatuntajree min tahtiha al-anharu waAAda Allahila yukhlifu Allahu almeeAAad

But those who have feared their Lord - for them are chambers, above them chambers built high, beneath which rivers flow. [This is] the promise of Allāh. Allāh does not fail in [His] promise.

But, for those who fear their Lord, there are chambers with chambers built on top of them, with rivers running from underneath them. This is Allah’s promise. Allah does not go back on any promise.