Quran 73:17

فَكَيْفَ تَتَّقُونَ إِنْ كَفَرْتُمْ يَوْمًا يَجْعَلُ الْوِلْدَانَ شِيبًا

Then how shall ye, if ye deny (Allah), guard yourselves against a Day that will make children hoary-headed?-