وَإِذا تُتلىٰ عَلَيهِم آياتُنا بَيِّناتٍ ۙ قالَ الَّذينَ لا يَرجونَ لِقاءَنَا ائتِ بِقُرآنٍ غَيرِ هـٰذا أَو بَدِّلهُ ۚ قُل ما يَكونُ لي أَن أُبَدِّلَهُ مِن تِلقاءِ نَفسي ۖ إِن أَتَّبِعُ إِلّا ما يوحىٰ إِلَيَّ ۖ إِنّي أَخافُ إِن عَصَيتُ رَبّي عَذابَ يَومٍ عَظيمٍ

And when Our verses are recited to them as clear evidences, those who do not expect the meeting with Us say, "Bring us a Qur'an other than this or change it." Say, [O Muhammad], "It is not for me to change it on my own accord. I only follow what is revealed to me. Indeed I fear, if I should disobey my Lord, the punishment of a tremendous Day."