سورة Az-Zumar 39:13

قُلْ إِنِّىٓ أَخَافُ إِنْ عَصَيْتُ رَبِّى عَذَابَ يَوْمٍ عَظِيمٍۢ ١٣

Say, “I truly fear—if I were to disobey my Lord—the torment of a tremendous Day.”