(Al-Kahf) 18 : 14
وَرَبَطْنَا عَلَىٰ قُلُوبِهِمْ إِذْ قَامُوا فَقَالُوا رَبُّنَا رَبُّ السَّمَاوَاتِ وَالْأَرْضِ لَنْ نَدْعُوَ مِنْ دُونِهِ إِلَٰهًا ۖ لَقَدْ قُلْنَا إِذًا شَطَطًا
And We braced their hearts when they stood up and said: "Our Lord is the Lord of the heavens and the earth. Never will we invoke any deity besides Him; if we invoke so, then we would be among the unjust.
It is told in verses 41: 30-32: “Indeed, those who have said: ‘Our Lord is Allah’ and steadfast in that declaration, the Angels will descend upon them by saying: ‘You don’t fear or grieve, but receive the Herald of Paradise that you were promised with. We are your protectors in the worldly life and the Hereafter. And you will have in it whatever your soul desire, and you will have in whatever you seek as accommodation from the Forgiving, the Merciful’". See explanation 4: 174-175.