Say, "Indeed I fear, if I should disobey my Lord, the punishment of a tremendous Day."
The Saheeh International Quran Translation
قُلْ إِنِّىٓ أَخَافُ إِنْ عَصَيْتُ رَبِّى عَذَابَ يَوْمٍ عَظِيمٍSay, "Indeed I fear, if I should disobey my Lord, the punishment of a tremendous Day."