At-Tawbah 9:89

aAAadda Allahu lahum jannatintajree min tahtiha al-anharu khalideenafeeha thalika alfawzu alAAatheem

Allāh has prepared for them gardens beneath which rivers flow, wherein they will abide eternally. That is the great attainment.

Allah has prepared for them gardens beneath which rivers flow where they will live forever. That is the supreme achievement.