﴿ قُلْ إِنِّىٓ أَخَافُ إِنْ عَصَيْتُ رَبِّى عَذَابَ يَوْمٍ عَظِيمٍۢ ﴾

“Say: "Behold, I would dread, were I [thus] to rebel against my Sustainer, the suffering [which would befall me] on that awesome Day [of Judgment]."”

Please check ayah 6:16 for complete tafsir.