(Al-Kahf) 18 : 3
مَاكِثِينَ فِيهِ أَبَدًا
In which they will remain in It eternally.
It is told in verses 43: 77-78: “And the inmates will call: “Oh Malik, let your Lord put an end to us!’; He will reply that ‘indeed you will remain in It eternally, surely We had come to you with the Truth, but most of you were hating the Truth’". See explanation 2: 25 and 3: 136.