Hud Ayah 26

أَن لَّا تَعْبُدُوٓاْ إِلَّا ٱللَّهَ‌ۖ إِنِّىٓ أَخَافُ عَلَيْكُمْ عَذَابَ يَوْمٍ أَلِيمٍ ٢٦ that you should worship none but Allah. I truly fear for you the torment of a painful Day.”