Say, “Indeed, I fear the suffering of a tremendous time, if I rebel against my Rabb (if I ignore His absolute administration within my existence)!”
Al-muntakhab fi tafsir al-Qur'an al-Karim
And say to them: "I am fearful of offending Allah, my Creator, for if I were to disobey Him, heaven shall lay my transgression to my charge and requite me in Day of Judgement with the torment laid upon the damned"