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 Allah. Allah does not fail in [His] promise.
English Transliteration
Lakini allatheena ittaqaw rabbahum lahum ghurafun min fawqiha ghurafun mabniyyatun tajree min tahtiha alanharu waAAda Allahi la yukhlifu Allahu almeeAAada
Tafsir of Verse 20
But those who fear their Lord -- for them await lofty chambers, above which are built lofty chambers, underneath which rivers flow -- God's promise; God fails not the tryst.
But it is for those who fear their Lord. That lofty mansions, one above another, have been built: beneath them flow rivers (of delight): (such is) the Promise of Allah: never doth Allah fail in (His) promise.